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close this bookReversing the Spiral - The Population, Agriculture, and Environment Nexus in Sub-Saharan Africa (WB, 1994, 320 p.)
close this folder4. The Nexus of population growth, agricultural stagnation, and environmental degradation
View the documentThe main linkages
View the documentTraditional crop cultivation and livestock husbandry methods
View the documentLand and tree tenure systems and the Nexus
View the documentDeforestation, fuelwood, and the Nexus
View the documentLogging
View the documentNotes
View the documentAppendix to chapter 4

The main linkages

The preceding chapter cited evidence suggesting that agricultural stagnation and environmental degradation, combined with customary land tenure systems and the traditional roles of rural women, may contribute to maintaining high fertility rates. These systems and practices appear to create demand for child labor as a means to ensure family survival. The difficulties faced in analyzing these relationships are rooted in the multiplicity of factors that affect the rate of population growth, environmental degradation, and the pace and direction of agricultural development in Sub-Saharan Africa In addition, there are important variations across countries. This chapter pursues the analysis of multiple and synergetic links between rapid population growth, poor agricultural performance, and environmental degradation. The role of women in rural production systems, a major link in this nexus, is discussed separately in Chapter 5.

The complexity of these linkages and the seeming ambiguity of the analysis result primarily from Boserup's finding that agricultural intensification occurs as population density on agricultural land increases (Boserup 1965). Others have published more recent materiel confirming the applicability of the Boserup hypothesis to many developing country situations, including in Sub-Saharan Africa (for example, Binswanger and Pingali 1984,1988; Pingali, Bigot and Binswanger 1987; Lele and Stone 1989). It should not be surprising that this phenomenon has been observed so widely Farmers are unlikely to have an incentive to intensify their agricultural production (i.e., to generate more output per unit land area) unless there is a constraint on land If there is no land constraint, and land is free or very cheap, it makes sense from the fanner's perspective to extend the use of land and minimize the use of other inputs, including capital and labor. Shifting cultivation and pastoral livestock raising are perhaps the best illustrations of this situation. They have predominated in most of Sub-Saharan Africa.

Box 4-1 Ukara Island, Lake Victoria (Tanzania): Agricultural Intensification under Population Pressure

An extreme example of agricultural intensification underpopulation pressure is that of Ukara island in Lake Victoria. Faced with considerable population pressure and soils of low fertility, the island's inhabitants, the Kara (or Wakara), had developed, prior to European contact, a highly refined intensive farming system, which included erosion control, crop rotation with intercropping and green manuring with legumes, fodder cultivation, stabling of cattle, and fertilizing of fields (farmyard manure, leaf manure, household ash). The tenure system was based on private property, with inheritance and sale of land. The system has, however, reached its limits. The island's population has numbered about 16,000 since the beginning of the century; population density is about 500 per km², and the average family holding amounts to 1 hectare of arable land. There has been little, if any, population growth, whereas there has been substantial population growth in the rest of the Lake area where shifting cultivation is still practiced. Excess population moves to the mainland, where labor-intensive techniques are quickly abandoned because the returns to labor are far higher with the extensive systems still possible on the mainland (Ludwig 1968; Kocher 1973, Ruthenberg 1980:158-160; Netting 1993:52-53).

Consistent with Boserup's findings, these customary extensive farming and livestock systems change when populations become more dense This can be seen in the Kenya highlands, Burundi, Rwanda, the Kivu Plateau in eastern Zaire, and in parts of Nigeria. In Rwanda in particular, intensive traditional agricultural systems exist, brought about by the scarcity of land relative to the population dependent on it. In most of Sub-Saharan Africa, however, land has been abundant until recently, and in some countries it still is.

Traditional crop production and animal husbandry methods. traditional land tenure systems and land use practices, traditional methods of obtaining woodfuels and building materials, and traditional responsibilities of women in rural production and household maintenance worked well and could evolve slowly when population densities were low and populations were growing only slowly The hypothesis is that rapidly increasing population pressure in the past twenty to thirty years has, in most of SubSaharan Africa, overwhelmed the only slowly evolving rural traditions of farming, livestock raising, fueIwood provision, land allocation and utilization, and gender-specific responsibilities in household maintenance and rural production systems This has led to an accelerated degradation of natural resources. And this in turn has contributed to the low rate of growth of agriculture. In those few places where agricultural intensification has occurred most rapidly, there has been very riffle, if any, degradation of natural resources.

Box 4-2 The Kofyar in Nigeria: Extensive Farming When the land Frontier Opens

The Kofyar initially lived as subsistence farmers on the Jos Plateau in northcentral Nigeria. As population density on the escarpment increased, they intensified their farming system, with increasing reliance on agroforestry, terracing, and manuring. When population growth on the plateau outpaced the ability of their farming system to sustain the increased numbers, the Kofyar obtained permission from tribes in the Benue River plains to clear low-land forests and farm there. The migrants abandoned the intensive farming techniques they had practiced on the plateau and adopted instead an extensive forest-fallow farming system focused on cash cropping and market-oriented animal production. The subsistence farms on the Jos Plateau had averaged about 15 acres, while the new farms in the cleared forests were 4 to 5 times that size (Netting 1968; Stone 1984). However, over a period of about thirty years, as population density in the newly developed lowlands increased, the settlers gradually intensified their farming methods again (Netting 1993).

The complexity of these multiple interrelationships is further increased by interaction with the economic policy environment characterizing many African countries since the mid-1960s. Exchange rate, tax, trade, and agricultural price policies in many African countries have often combined to render agriculture unprofitable. The mechanisms for developing and trsnsmitting improved agricultural technology are severely inadequate throughout Sub-Saharan Africa. Excessive government control of agricultural marketing and processing has either squeezed out the private sector or forced it to operate clandestinely, yet public sector marketing; and processing enterprises have performed poorly Farmers have not usually been permitted to associate freely in farmer-managed cooperatives, nor to market freely their products Throughout Sub-Saharan Africa, this lack of empowerment of farmers has discouraged them from investing To break out of the trap of rapid population growth, low agricultural growth, and environmental degradation, these policy constraints must be overcome. The World Bank's 1989 long-term perspective study on Sub-Saharan Africa suggested how this might be done (World Bank 1989d). Reversing the Spiral contends that measures will also be needed to overcome the constraints imposed by increasing population pressure on traditional cultivation, fuel provision, and tenure systems, and by the roles customarily assigned to women in rural societies. Appropriate policy reforms will make the more rapid evolution of these traditional systems easier.

Traditional crop cultivation and livestock husbandry methods

For centuries, shifting cultivation and transhumant pastoralism have been, under the prevailing agroecological conditions and factor endow ments, appropriate systems for people throughout most of Sub-Saharan Africa to derive their livelihood, in a sustainable manner, from the natural resource endowment of their environment The ecological and economic systems were in equilibrium. The key to maintaining this equilibrium was mobility. People shifted to a different location when soil fertility declined or forage was depleted, allowing the fertility of the land to be reconstituted through the natural processes of vegetative growth and decay. For field cropping in forest- and bush-fallow systems, this typically involved cultivation periods of two to four years, land then being left fallow for as long as fifteen to twenty-five years. Transhumant herders' mobility generally involved a far greater geographic range, but a far shorter temporal cycle They would move the herds on extended migratory patterns as dictated by the seasonal availability of water and forage and in most cases repeat the same cycle in one or sometimes two years.

These mobile systems of shifting and long-fallow cultivation and pastoral transhumance were suitable because of low population density, abundant land, limited capital and technology, and often difficult agroclimatic conditions. As long as population growth was slow and land was available, the additional people could be accommodated by gradually taking more land into the farming cycle and establishing new settlement; on previously uncropped land. Adjustments, including gradual intensification of farming, were made as and when they became necessary, but the pace of adjustment required was slow because population growth was slow. Intercropping in Rwanda, for example, was an indigenous adaptation of this type, necessitated because shifting cultivation became increasingly constrained by rising population density.

In the absence of sufficiently rapid and widespread technological change, population growth has led to the expansion of the area under cultivation This has involved mainly the conversion of large areas of forests, wetlands, river valley bottoms, and grassland savanna to crop land. Since 1965, the area farmed in SSA has increased by over 21 million hectares (Table A-17). Much of this has taken place on ecologically fragile and agriculturally marginal land, which is not suitable for sustained farming and eventually abandoned in an advanced state of degradation. Forested land has declined by about 65 million hectares since 1965 (Table A-17) But land available to expand cultivation has become increasingly scarce in most of Sub-Saharan Africa, drastically narrowing the scope for further expansion. Most farming systems in SSA are, in fact, not land surplus systems, but landextensive systems (Eicher 1984a:455). Over the past twenty-five years, crop acreage has expanded by only 0.7 percent annually, and the population pressure on cropped land has increased sharply. On average, per capita arable land in Sub-Saharan Africa declined from 0.5 hectares per person in 1965 to 0.4 ha/person in 1980 and to less than 0.3 ha/person in 1990. For comparison, between 1965 and 1990 crop acreage declined from 0.6 ha/person to 0.4 ha/person in China and from 03 ha/person to 0.2 ha/person in India (Table A-18).

Box 4-3 Land Requirements for Chitemene Cultivation in Zambia

The suitability of land for chitemene cultivation in Zambia depends, among other things, on the density of woody vegetation available for cutting and on the land's regeneration capability. At the present levels of fram technology and productivity, a person completely dependent on chitemene requires for survival one hectare under cultivation each year (Stolen 1983:31-32; Vedeld 1983:98-100) If 50 percent of the land in an area is suitable for chitemene and the regeneration cycle is twenty-five years, the aggregate land requirement for long-term ecological sustainability of the system is 50 ha per person. In a village of 200 people, requiring a total area of 100 km, to sustain chitemene farming, individual fields would be as far as 5.1 km from the village—assuming the village land forms a perfect circle and the village is located in its center.

This simple arithmetic also shows that traditional farming and land use practices, combined with constraints on the time people can afford to spend walking to and from their fields each day, limits the size of farm settlements. Some people eventually migrate to establish new villages in virgin forest land once the situation in their home village becomes too difficult.

Because of agroclimatic and soil characteristics, the potential productive land endowment per capita in most of Sub-Saharan Africa is even poorer than these simple acreage statistics suggest. Niger, for example, is more densely populated than India or Bangladesh if account is taken of the extremely poor quality of its agricultural resource endowment Nigeria and Senegal are more densely populated than the Philippines. And Mali, Burkina Faso, and The Gambia are twice as densely sealed as Indonesia (Binswanger and Pingali 1987; Matlon 1990).


Figure 4-1 Population Pressure on Cropland in Sub-Saharan Africa, 1961-1987 (total and rural population per hectare of cropland)

There is considerable diversity among countries, but everywhere fallow periods are shortening as populations increase and the land frontier recedes. In many areas, from Mauritania to Lesotho, fallow periods are not sufficiently long anymore to restore soil fertility. Increasingly farmers are compelled to remain on the same parcel of land—yet they change their farming methods only very slowly.

These people face a critical dilemma: a central element of their traditional farming system—the ability to shift around on the land—is teeing eliminated by population pressure, yet they continue to use the other elements of their customary production systems. Where fallow periods are too short, or nonexistent, and where traditional cultivation techniques continue to be used, soil fertility deteriorates and soils are not conserved. Wind and water erosion, soil nutrient depletion, acidity, and deteriorating soil structure become common and increasingly severe. As a result, crop yields decline, forcing farmers to expand production along the already receding land frontier. This expansion occurs first within the vicinity of their settlements—on more steeply sloping land and in nearby forest, wetland and range areas. As this option becomes increasingly limited, people migrate to establish new farms, often in semiarid areas and in tropical forests where soil and climatic conditions are poorly suited to the cultivation of annual crops and yields are therefore low. The migrants bring with them the techniques they practiced in the areas they abandoned, and these techniques are often detrimental to their new environment. Although they soon begin to experiment with simple modifications in farming techniques, this indigenous adjustment has almost everywhere been too slow to keep pace with population growth in the past two to three decades.

Good pasture land is diminishing as the most productive tracts are converted to cultivation. The mobility of pastoralists' herds is further reduced as settlers increasingly cultivate bottomlands previously avaiIable to herders during their dry season migration. The concentration of increasing numbers of livestock on smaller areas destroys pasture vegetation, further reducing their carrying capacity and contributing to range degradation and eventual desertification (Gorse and Steeds 198;7; Falloux and Mukendi 1988; Nelson 1988).

Diminishing forest and woodland resources provide less fuelwood and other fores/products, many of which are of considerable importance for rural livelihood and survival systems. Similarly, surface and groundwater resources are increasingly affected by the drastic alterations in land uses and vegetative cover The effects of the worsening fuelwood and water scarcity are most directly felt by some of the most vulnerable: women and children. More time and effort are required to obtain these vital commodities. Or people must manage with less of them. One consequence of reduced woodfuel supplies is the increasing use of dung and crop by-products as fuels. This reduces their availability as farming system inputs to maintain soil fertility. Similar effects result from diminished availability of, and access to, water for household and home garden use: health and sanitation standards deteriorate, and home garden productivity declines.

These problems are gravest in parts of the Sahel and of mountainous East Africa and in the dry belt stretching from the coast of Angola through southern Mozambique. There are other countries where land appears to be more abundant in relation to their current populations These countries lie in Central Africa, humid West Africa, and southern Africa. However, much of the potentially arable land in Central and humid West Africa is under tropical forest To preserve biodiversity, maintain rainfall, and preserve the humid climate on which its tropical agriculture is based, much of this area should not be cultivated. Instead, the humid forests need to be preserved. This land has not been cultivated so far because it is poorly suited to cultivation (except possibly of certain tree crops). Soils in Africa's rain forest zones are typically low in nutrients and of high acidity. Yet even in these snore land-abundant countries, the problem that is the focus of this study can already be observed. An expanding population depending on agriculture and livestock is moving into the tropical forest areas, extending crop production and grazing into areas that are agroecologically unsuited to these forms of land use.

No analysis is available that quantifies the impact of environmental degradation caused by more people practicing traditional shifting cultivation and transhumant and pastoral livestock raising. It has therefore not been possible to separate the contribution of this phenomenon to poor agricultural performance in Sub-Saharan Africa from that of the policy problems identified earlier. There appears to be little doubt, however, that these policy deficiencies have slowed the evolution of ancestral systems into systems more sustainable with higher population density. (A statistical test of this hypothesis is summarized in the Appendix to Chapter 4.)

Land and tree tenure systems and the Nexus

Critics of traditional tenure systems in Sub-Saharan Africa argue that these constrain agricultural productivity and cause environmental degradation—because land resources are not privately owned, but arc either common property of a community, clan, or ethnic group or are openaccess resources owned by no one. They further argue that users of such resources have no incentive to limit their consumption thereof because they cannot be certain that other users will similarly limit theirs. Lacking secure property rights, individuals are dissuaded from adopting long-term conservation, investment and production strategies. There are two possible solutions, it is argued, to this problem: (a) establishing firm rules, with enforceable sanctions, which limit individual use of the resource for the common good; or (b) individualization/privatization of resource ownership and tenure, and registration of individual titles. In the critics' view, rapidly rising population pressure makes effective common ownership regulation increasingly mere difficult Based on the "tragedy of the commons" argument, they urge that land be placed in individual private ownership.

Opponents of tenure individualization focus on its alleged negative impact on land distribution and social equity Evaluations of tenure reform in Kenya and Botswana are cited as showing that individualization of land tenure has led to land grabbing, concentration of land ownership, de facto expropriation of women, landlessness, and increasing marginalization.

Box 4-4 Examples of Indigenous Land Tenure Systems

In The Gambia, each village has an identifiable land area that is administered by the village headman. Any compound can clear unclaimed land outside the village jurisdiction and claim it for the village. Land is passed on through the male lineage. Women obtain land for farming mainly from their husbands, but also receive some from their parents. Men cultivate groundnut, millet, and sorghum; women grow rice and vegetables. Maize is grown by both men and women. Women help with millet and sorghum harvesting and are beginning to grow some groundnuts. Seasonal migrants from other parts of the country or from Senegal (strange farmers) can obtain land for cropping in return for working several clays each week on the fields of the compound head) they return to their own villages at the end of the cropping season (Norem and others 1988:303-304).

In Tanzania, land was traditionally controlled and allocated by patriarchal clan leaders to heads of households or extended families. Today, all land is owned by the state, and the "Village Act" requires that each member of the village, male or female, be assigned separate plots to cultivate specific crops that are designated in the village bylaws. It is reported to be widespread practice for land to be allocated to male house-hold heads, who in turn assign plots to their wives, sons' and daughters. Often, vestiges of the traditional system remain, and the original users, usually males, retain some right over land even if it is currently lying fallow (Mtoi 1988:346).

Among the Bemba in Zambia, landholdings are semipermanent. Local chiefs allocate land according to farmers' ability to cultivate (dependent especially on the availability of draft power). Tenure is based, thus, on customary rights allocated by local chiefs and secured through clearing and continuous use of particular plots. Land use rights are passed on through the matrilineal kinship system. Farm sizes are large, averaging close to 100 hectares, but only about 5 percent of the farm is actually cultivated at any given time under the land-extensive traditional farming system (Hudgens 1988:373-387; Sutherland 1988:389 406)

Reality is far more complex. There is a wide diversity of farming systems in Sub-Saharan Africa, determined by differences in population density, agraecological conditions, sociopolitical organization, lineage and descent definitions, inheritance and residence patterns, agricultural technology, and degree of commercialization. The correspondingly wide range of seemingly different land tenure systems is therefore not surprising. There are, however, important similarities among most of them. Most define land rights, particularly ownership rights, for groups. Individual or family use rights rest on customs recognized by the group. The group, not the individual, owns the land—although there is no formal recording or land titling. An individual's entitlement to the land is transitory, although in most cases lineages enjoy continuous use rights over specific parcels. As fallow periods become shorter and cultivation of plots becomes more continuous, land is increasingly retained by families, households, or individuals and transferred or bequeathed under prevailing customary rules (Migot-Adholla and others 1991; Netting 1993:157-164). There is, thus, gradual institutional change in response to rising population pressure, and this change accompanies and facilitates the evolution and intensification of agricultural production.

Customary tenure systems involve important intricacies. Ownership, management responsibility, and use rights are often not identical. Use rights to different products from the same piece of land may be vested with different individuals or groups. Pastoralists and sedentary farmers may coexist on the same land, with farmers having cultivation rights and pastoralists grazing rights after crops are harvested. On the same plot of Land, the right to the products of trees and the right to plant annual crops may be quite distinct and vested in different individuals or groups (see below).

Where, under customary tenure systems, usufruct rights are acquired simply by clearing land, the incentive has been strong for settlers to move into previously uncultivated forest or savanna areas and to clear the land quickly in order to strengthen their claims and weaken those of other potential (even current) users. In Mali, for instance, many farmers plow far more land than they intend to crop in order to establish and protect their land use rights for the future. (Plowing without establishing crops renders the Land even more vulnerable to erosion than if it were cropped.) Even under government-sponsored land development schemes, the ability to clear, rather than to develop, the land is often a key determinant of eligibility.¹ This extends cultivation to marginal lands, is environmentally detrimental, and imposes costs on the previous users—often pastoralists or traditional forest dwellers.

As fallow periods shorten or valley bottoms are taken under cultivation. land rights of farmers tend to take precedence over those of herders, who are then forced to remain on more marginal and more rapidly degreding rangeland. Where sedentary farmers and transhumant herders have coexisted in symbiotic land use systems, the incorporation of livestock activities into settlers' farming systems also tends to cause difficulties for the pastoralists, who are then compelled to keep their herds increasingly on pasture land alone. As a result, soil fertility declines more rapidly on such rangeland (Gorse and Steeds 1987; Stocking1987; Falloux and Mukendi 1988; Nelson 1988; Mortimore 1989a and 1989b).

Box 4-5 Land Tenure and Gender Roles in Farm Production among the Fula and Mandinga in Guinea-Bissau

Among the Fula and Mandinga in Guinea-Bissau, land is communally owned by the resident clans of the village and is allocated by the male clan elders to the individual compounds. The male compound heads then allocate land to the individuals within their compounds. Use rights can be granted on a collective or individual basis. Men and women, married or not, can obtain use rights to individual plots and have the right to dispose of the harvest from these.

Collective fields remain under the control of the compound head, who is responsible for maintaining the collective granary, and work on collective fields has priority over work on individual plots.

Grasslands around the settlements are farmed exclusively by men, in a grass-fallow rotation of four-to-eight-year cycles, with sorghum, millet, fonio, cassava, groundnuts, and cotton. Male collective fields must be planted with subsistence crops (millet, sorghum) for home consumption. Male cash crops (groundnuts, cotton, cassava) are grown only on males' individual plots. Upland forest areas are used, with men and women working together, in long cycle slash-and-bum shifting cultivation to grow upland rice, millet, maize, and tubers.

River valley land with sufficient moisture is utilized and controlled exclusively by women; they make all planting decisions and have the right to distribute and/or sell the product from their individual fields. Female collective and individual fields are always located in the valley bottoms and are used for rice cultivation. The clans' senior women allocate this land to the individual compounds, and the senior woman of each compound is responsible for the compound's collective fields and allocates individual plots to the compound's women. The senior women also hold the rights to the oil palms in the valley bottoms.

All women receive from the village elders rights to water and land for gardens where they grow vegetables; they have the right to dispose of the produce of then garden.

Some men grow cassava, cocoyam (taro), maize, sweet potato, and beans in their own gardens (Lifton 1991:1-19).

In many customary tenure systems, land for farming is assigned to eligible claimants on the basis of their ability to dear it and to establish field crops. In others, bush or forest fallows tend to revert to communal authority and can be reassigned to another claimant. The shortening of fallows may therefore also be the result or the cultivator's attempt to safeguard his or her rights to the plot. Because land is becoming scarce, shortened fallows may also be caused by someone else moving in too soon after the previous cultivator has left the plot to natural regeneration.

Understanding the complexities of local tenure systems is especially important for comprehending the incentive system that applies to agroforestry activities. It also often helps explain deforestation. Tree tenure may be distinctly different from land tenure.² One person or group may have rights to the land, while others have rights to the trees on it, or to certain products from certain trees at certain times. In northern Sudan, for instance, a tree and its fruits may belong in shares to the owner of the land, the person who provided the seedling, and the owner of the waterwheel that irrigates the land (Gregersen and others 1989:156). In some systems, tree clearing may be the only way to establish uncontested usufruct rights for cultivation. Elsewhere, tree planting may be regarded as laying claim to land In many areas, diverse arrangements concerning rights in trees are common and of considerable relevance to those deciding whether to plant trees and which trees.

Tree tenure issues are particularly critical where deforestation is severe and the fuelwood crisis pressing, but also where tree crops have potential for environmentally sustainable and profitable agricultural development. In some countries, because all forest land is owned by the state, people may fear that if they plant trees their land will revert to the government. In parts of the Sahel, people have been unwilling to plant certain trees because these are on the forest department's protected list, and to cut or prune them would require going through tedious procedures to prove they own the land and planted the trees and to obtain cutting permits (Timberlake 1986).

Box 4-6 Tree Tenure Rights

Tenure rights in to trees comprise a variety of specific rights, primarily

· Use rights include: (a) gathering rights—for example, the right to gather or lop dead branches for fuelwood, to gather things growing on a tree (such as fungus or insects), or to gather tree products from under the tree, such as fallen leaves or fruit; (b) use of the standing tree—such as hanging honey barrels in it, (c) cutting parts or all of a living tree—for livestock fodder or building material, for instance; (d) harvesting produce

· Disposal rights comprise the right: (a) to destroy (by uprooting or felling individual trees) or to clear a section of forest; (b) to lend; (c) to lease, mortgage, or pledge; (d) to bequeath; and (e) to sell (Gregersen and others 1989:155-157).

A recent study in Ghana, Kenya, and Rwanda found that customary land tenure systems do not appear to be insecure (Migot-Adholla and others 1991). Many farmers enjoy transfer rights on their lands—although these rights may be subject to approval by family or lineage members. Women's tenurial security is generally far less certain than that of men (see Chapter 5), but the opposite may be the case in some matrilineal-matrilocal societies. To the extent that the social system sanctions transactions in land, such transactions are sufficiently recognized. Traditional tenure systems continue to evolve, and many have over time accommodated increasing degrees of individual ownership and management control. Rapid population growth and growing commercialization of agriculture increasingly necessitate investing in land management and improvement, hastening the individualization of land rights (Migot-Adholla and others 1989).³ In many cases, private rights to land have become virtually exclusive, although they fall short of outright ownership Other members of the community may have secondary concurrent or sequential rights that permit, for instance, fuelwood collection or livestock grazing. Inheritance has emerged as the most significant form of acquisition of agricultural land in traditional rural society, and rights to such land are very secure; nevertheless, security of tenure is strengthened by continuous occupation and cultivation Restrictions on the sale of inheritable land may still apply in some systems (as in the northern Mossi Plateau in Burkina Faso), but in others land has been sold for half a century or more and can be mortgaged and leased (as in the Hausa areas of southern Niger and northern Nigeria). Purchases are becoming an increasingly important means of acquiring land. This is occurring in Kenya, with its history of land registration and government intervention in land matters' but also in Ghana and Rwanda' where governments have been less active in providing and enforcing a welidefined legal framework for land transactions (Migot-Adholla and others 1989).

Problems arise as traditional tenure systems begin to impose constraints on evolving agricultural production systems and on the adoption of technological change. Unfortunately, most African governments and external aid agencies have mistakenly believed that traditional community ownership of land did not provide adequate tenurial security, and that it discouraged investment in the land This perception arose largely from failure to understand fully the intricacies of customary tenure systems with their emphasis on venous user rights and the often subtle, but important, differences among different communities arrangements. A particularly important aspect of most, if not all, ancestral African land tenure systems—the concept of the inalienability of land—has been widely regarded as an obstacle to agricultural development: land markets did not readily develop, and individual land ownership was difficult to establish as collateral for institutional credit. (Of course, smallholders anywhere in the world are extremely reluctant to mortgage, and hence risk losing, their land).

There has also been an erosion and breakdown in customary laws and rules governing sustainable use and management of land and other common property resources. This has occurred under the pressure of rapid population growth and has been exacerbated by large-scale rnigration in many countries and by changing social values and customs. Increasing commercialization of agriculture has induced changes in land use, farming systems, and cropping patterns. Inappropriate pricing signals arising from government interference in input and output markets have often hastened such changes into unsustainable directions. And central authorities have frequently undermined the capability of local decisionmaking bodies to manage their natural resource environment by imposing tight controls over local organizations, removing authority to central agencies, and creating new organizations that compete or conflict with traditional ones (Blaikie and Brookfield 1987; Gorse and Steeds 1987). In many areas, resources that were under effective communal management have, as a result, been converted into de facto open-access resources (e.g., Nekby 1990).

The response of many governments has been to nationalize land ownership' but then to allow customary law to guide the use of some land while allocating other land to private investors, political elites, and public projects. This has reduced, not increased, tenurial security. Investing in the land becomes risky for farmers, since governments can and do reallocate land to serve "national purposes." In many cases this accelerates the breakdown of customary land management systems and emergence of openaccess conditions in which exploitation by anyone is permitted.

In much of the West African Sahelo-Sudanian Zone, for instance, pasture end even croplands are often treated as a free good under current policies Wells have been sunk to permit access to ostensibly unexpIoited or underexploited rangeland, and settlers in less densely populated areas are not subject to any land use guidelines. In both cases, legal incentives would help by offering land rights in exchange for management responsibilities (Gorse and Steeds 1987). In most countries, forest land has been taken over by governments, overriding the rights of indigenous populations. Though nominally controlled, these "protected" or "reserved" forests have become virtually open-access resources for large - and small scale exploitation, because the responsible agencies have not been able to provide effective management.

Box 4-7 Common Property vs. Open-Access Regimes

There is much misunderstanding of the difference between common property and open-access regimes. Open-access resources are at great risk of over-exploitation, since they lack clearly defined ownership and use rights assignations as well as effective management. Common property systems, by contrast, are well-structured arrangements in which group size is known and enforced, management rules are developed, incentives exist for co-owners to adhere to the accepted arrangements, and sanctions work to ensure compliance. There is a set of agreements within the community over the rights to use of communal land resources by venous members and/or subgroups of the community and by strangers, even in sparsely settled areas. Communal land really means not so much communally managed land, but land to which members of the community have rights, while outsiders do not or only under specific and tightly prescribed conditions (Repetto and Holmes 1983; Blaikie and Brookfield 1987; Bromley and Cernea 1989; Barnes 1990a).

Open-access systems, found especially in forest and range areas, result in rapid environmental destruction—a repetition of the process widely observed before the agricultural transformation in Europe and usually (albeit mistakenly) labeled "the tragedy of the commons." Openaccess systems are not conducive to resource conservation or to investment in land This problem was resolved in Europe largely by the allocation of land to individual owners who then had an incentive to invest in it, develop it, and conserve it.

As noted earlier, there may be a further problem in open-access systems, which may also be a problem of customary tenure systems In most of rural Sub-Saharan Africa, access to nonfamily labor is limited. Hiring wage labor is rarely an option, simply because there is, as yet, no class of landless laborers, although population pressure is leading to the emergence of seasonal and migrant wage labor in rnany countries. More common in many communities is the pooling of labor for certain tasks, sometimes among gender and age mates within a village, more often among members of a larger kinship group. Granting access to land for farming to members of a community on the basis of their ability to cultivate it may therefore be a disincentive to control human fertility, because the ability to cultivate land is generally determined by the ability to mobilize family labor (e.g., Amankwah 1989:21). Field studies report this to be an important incentive to increase family size through polygamy and pressure on women to bear many children.

The "solution" often proposed to overcome these various problems is the allocation of individual land titles, through large-scale titling programs. But the experience with such programs has been poor. Individualized land titling in Kenya and Botswana has facilitated land grabbing, concentration of ownership, and concomitant landlessness. In Nigeria, large tracts for which members of the political and economic elite obtained occupancy certificates under the provisions of the 1978 Land Use Act have been rapidly cleared of vegetation with motorized equipment so as to preclude any possibility of smallholders remaining or becoming active on such land; this has been an effective way of eliminating potential contestants to land claimed under the provisions of the Act, but it has also been extremely abusive of the environment. Such land grabbing had been practiced by European colonists, and some of the new elites have used the same methods.

However, the problems in Kenya, Botswana, and Nigeria may be associated more with the problem of transition from traditional to modern tenure systems. The rights of customary land and tree owners were largely disregarded, and members of the political and economic elite too easily manipulated the legal and administrative systems to wrest land from its traditional owners. However, once obtained, individual land ownership does provide an incentive to develop and maintain the land. This can be witnessed in the intensive sustainable farming practiced by smallholders in the Kenyan highlands, by private landowners in Zimbabwe and Botswana, and on tree crop plantation in Cd'Ivoire.

To avoid the problems associated with an unduly rapid move to private individual titling, or the even greater problems of nationalizing land ownership, it will be prudent to establish legal recognition and protection of customary tenure systems, combined with an effective and transparent mechanism to provide individual or group titles on demand and only with the agreement of the traditional landowners and users (such as pastoralists). Only a demand-ariven process of individual land titling will be possible and advisable However, as traditional land tenure systems break down, and to resolve existing problems in open access systems), land titling wiIl be necessary for agricultural growth, soil conservation, and forest protection.

Deforestation, fuelwood, and the Nexus

In arid and semiarid areas, the need for woodfuel is a major cause of the reduction in tree cover Excessive lopping and felling, combined with poor regeneration capability, have set in motion a downward trend that has been sharply accelerated by prolonged periods of drought and by increasing livestock on young regrowth. In many areas woodfuel extraction considerably exceeds natural regrowth. Fuelwood shortages in fact limit the "carrying capacity" of arid and semiarid West Africa more than do low crop and livestock yields (Gorse and Steeds 1987:13,28).

Woodfuels are the staple source of household energy, with 90 percent of all households using them for cooking, the main end-use of energy in Sub-Saharan Africa (Barnes 1990a). Some agroprocessing and rural artisanal and semi-industrial activities (such as fish smoking, tobacco curing, shea nut processing, pottery, brick making, smithies, distilleries, beer brewing) also use considerable quantities of woodfuels. In Malawi, 100 kg of firewood are used to cure 3-12 kg of tobacco, in Cd'Ivoire, 100 kg of wood are used to smoke 66 kg of fish (Dankelman and Davidson 1988). In many countries, woodfuels are used in industrial production as well (tanneries, cigarette and match production, breweries, tea factories). In the early 1980s, wood accounted for over three- fourths of total energy supply in thirteen of SSA's sixteen least developed countries (de Montalembert and Clement 1983). In urban areas, charcoal is partly replacing wood.

The fuelwood problem is a function primarily of population density and of agroclimatic and vegetation zone and is, therefore, very region and location specific A 1983 FAD study (de Montalembert and Clement 1983) identified the regions where people faced acute fuelwood scarcity or deficits. Populations facing "acute scarcity" were defined as those in areas where energy requirements could not be met even by taking wood on a nonsustainable basis or by making use of animal waste. Populations facing a fuelwood "deficit" are those in areas where fuel needs were met by taking wood on a nonsustainable basis. The most vulnerable areas include the arid and semiarid zones south of the Sahara as well as eastern and southeastern Africa and the islands and mountainous regions Fuelwood deficits were identified in the savanna regions of West, Central, and East Africa. The number of people affected by fuelwood shortages, already large, is expected to increase steadily:

· The arid regions face the most severe problem—with the woodfuel scarcity, rather than food production capability, imposing the more stringent limit on the land's carrying capacity

· In the more densely populated savanna zone, only 25 to 50 percent of total fuelwood needs can be met from annual regrowth; conditions for tree regrowth are generally favorable, but rapid population growth is causing problems

· In the less densely populated savanna, supply is still adequate for the resident population, but needs could rapidly outstrip supply in the absence of appropriate interventions.

· In Central Africa, with tropical forests and low population densities, woodfuel supplies are likely to be adequate well into the next century. However, increasing rates of cutting are contributing to deforestation and the resulting environmental problems.

· The coastal strip along the Gulf of Guinea has excellent conditions for tree growth, and tree plantations are widespread. Fuelwood supply is adequate, but this will change in the near future, especially around the large and rapidly growing urban concentrations.

· The densely populated highlands of eastern Africa already face woodfuel deficits. Reforestation efforts in Burundi and Rwanda, though rather successful, have been unable to keep pace with demand growth.

In 1980, eleven countries faced negative fuelwood supply-demand balances: Burkina Faso, Burundi, Chad, The Gambia, Kenya, Malawi, Niger, Rwanda, Swaziland, Tanzania, and Uganda (Table A-21). By the end of the century, Ethiopia, Madagascar, Mali, Nigeria, Senegal, Sierra Leone, Sudan, and Zimbabwe are expected to join this list Since a significant switch to other fuels is not likely or possible in the short to medium teen, population growth translates almost directly into a growth in demand for wood fuels (except to the extent that fuel efficiency is improved) Yet continued reliance on woodfuels is clearly threatened m many regions by unsustainable exploitation.

Over time, urbanization on will facilitate a switch to nonwood fuels, but urban Africa still depends very heavily on wood. Woodfuels are the fuel of the poor, including the urban poor. In many cities, as much as 90 percent of all households use woodfuels for cooking. Fuelwood prices in urban areas are high and rising In some cities spending on fuelwood now claims up to 20 percent of the income of poor households. Urban demand for woodfuels has been far more destructive of forest resources than rural fuelwood gathering, mainly because of inappropriate policies. Rapid urban growth has led to intense cutting of wood on a large scale around cities and along major roads. Wood is brought from considerable distances, charcoal from even farther, and there are steadily widening rings of deforestation around cities such as Ouagadougou, Dakar, and Niamey. Woodfuels are supplied to major cities in eastern Africa such as Mogadishu from as far as 500 km away.

Transport costs and trade margins account for most of the cost to urban consumers, and the cost of trucking woodfuels to urban markets is the main determinant of the distance from which wood fuels are brought. Where motor fuels are priced well below world market levels, as in Nigeria, the effect is to extend drastically the distances over which trucking of woodfuels to urban centers is profitable, and the impact even on distant forest resources is particularly severe. Woodfuel prices to "producers" (usually collectors or exploiters of forest resources, rather than actual producers) tend to be extremely low, often as low as 5 to 6 percent of the urban consumer price. This provides no incentive to produce fuelwood commercially. Given the wide spread between the stumpage price and the consumer price, higher stumpage fees, providing incentives for more-efficient harvesting and for fuelwood production, would have little impact on urban consumer prices (Barnes 1990a).

The commercialization of the urban fuelwood and charcoal economy has increased the utility of rural fuelwood sources. under subsistence conditions, local fuelwood resources were used only to meet local demand, but these resources can now also be exploited for sale outside Limited and inelastic subsistence demand is replaced by limitless and elastic export demand (from the standpoint of the local economy), leading to much more rapid rates of exploitation than would be implied by local population growth alone (Repetto and Holmes 1983). The collection of fuelwood and its sale in urban/pert-urban areas by poor rural women, on their own account or under contract to commercial traders, is an obvious example.

As studies in Botswana, Malawi, Nigeria, and Tanzania have confirmed, woodfuel demand first increases with rising income and later declines with increasing substitution of kerosene, liquefied petroleum gas (LPG), and electricity. The potential for such interfuel substitution depends heavily on economic growth and on income distribution in cities where economies of scale can be realized in meeting demand for fuel from such alternative sources. It also depends on pricing policies and supply security at the consumer level (Barnes 1990a). To the extent that slow economic growth and rapid population growth prevent significant increases in average per capita incomes, demand for woodfueIs will continue to increase about as rapidly as population growth Moreover, even if aggregate economic growth can be accelerated, but is inequitable and leads to widening disparities in income distribution, this will impede the switch to nonwood fuels.

The brunt of the fuelwood crisis falls on women: they must manage household energy needs through fuel collection, preparation' and use. Men do not usually involve themselves in fuel provision for the household under subsistence conditions, but there are exceptions (as among the Muslim Hausa); they usually take over only when the fuel economy becomes commercialized Children increasingly have to help their mothers with this task. Girls in particular have to help in fuelwood fetching, fuel preparation, cooking, and tending the fire In Tanzania, girls help their mothers as soon as they can walk. In many parts of Africa it is not uncommon for mothers to take their daughters from school to help them gather fuel. Women (and children) have to walk increasingly farther and take more time to collect fuelwood. In parts of Sudan, the time needed to fetch fuelwood increased more than fourfold between the mid-1970s and the mid-1980s (Agarwal 1986). This time is diverted from other pressing tasks—including timely crop planting and weeding (thus depressing crop yields) and childcare (which is increasingly entrusted to school-age girls kept at home). When fuelwood sources were more abundant, fuel gathering could often be combined with other activities, such as walking home from school or from the market or field. With increasing scarcity, fewer sources, and longer distances, the loads carried become larger and heavier, more time is required, and the opportunity to combine wood fetching with other tasks is reduced.

Women very rarely have access to any labor-saving technology for their task—transport aids or efficient tools for cutting or felling. They carry heavy loads to reduce the number of trips required to provide fuel for their household (and often their nonfarm income-earning activity as well). They may headload as much as 35 kg (even though in many countries 20 kg is the maximum legally permissible headload for women) over distances of up to 10 km, often over difficult terrain. Carrying such heavy loads damages the spine, causing difficulties during pregnancy and childbirth, uses up substantial energy, and is a cause of frequent accidents.

Fuel scarcity leads to changes in nutritional patterns, especially to fewer meals being cooked or meals being cooked less well (Timberlake 1986 :34). In parts of the Sahel, many families have gone from two to only one cooked meal per day (Agarwal 1986); others mix uncooked millet with water for a midday meal (Tinker 1987) A study in Rwanda found 62 percent of families cooking only once a day and 33 percent cooking even less often (Dankelman and Davidson 1988:71). Fuel shortages also induce shifts to foods that require less energy to cook, but may be nutritionally inferior. Women in Burkina Paso refused to use soybeans because of the long cooking time and greater fuel requirement compared with the traditional cowpeas (Hoskins 1979)—until they were taught to ferment the beans into soybean cake, which reduced the heating time from as much as twelve hours to one (Tinker 1987). Switching to raw or partially cooked food or to cold leftovers is becoming more common (Dankelman and Davidson 1988:71). The shortages of fuelwood, of food and of women's time combine into a serious nutritional and health problem Partial cooking can cause significant health problems. Water purification requires boiling—not possible without fuel and tune. Hot water to wash dishes, utensils, laundry, and children may be out of the question (Dankelman and Davidson 1988:71-72). The impact of nutrition and health problems on labor availability and productivity for farming and other income-generating activities is, of course, negative.

The intensifying fuelwood shortage has another important negative effect on rural women Many of their nonfarm income-earning activities require fuelwood: food processing, beer brewing, fish smoking, pottery making, etc. Fuelwood scarcity therefore severely limits their opportunities to supplement their income through such activities. This is an increasingly critical issue in view of the widespread gender-separation of budgets and women's almost exclusive responsibility for child rearing (see Chapter 5).

Eventually, women have little choice but to switch to other fuels. Interfuel substitution in rural Sub-Saharan Africa usually means a switch to less efficient fuels—most commonly to crop by-products and residues and dung, which are far more valuable if recycled as inputs into the farming system to help maintain soil fertility. Many such fuels are less convenient than firewood or charcoal, requiring more tending and fire-feeding, generating more smoke and less heat' and so on. Cooking may take longer and require even more fuel than before.

Using crop by-products and dung as fuel also has significant negative effects on soil fertility, water retention, crop yields, and soil degradation and erosion. This is increasingly happening, for example, in areas such as the Ethiopian highlands and the northern part of the Sahelo-Sudanian Zone. In Ethiopia, an active urban market for animal dung has developed where fuelwood resources have become depleted (Anderson and Fishwick 1984). The importance of agricultural wastes and dung for fertility management in farming systems is particularly critical as fallows are shortened and recycling of crop waste and dung is essential in the move towards agricultural intensification. Under the agroecological conditions of much of Sub-Saharan Africa, this is extremely important organic matter is quickly mineralized in the absence of shading tree canopies, and nutrients are leached rapidly from most soils. One study estimated that dung used as fuel in Ethiopia in 1983 would have increased the country's cereal output by 1-15 million tons if it had been used as fertilizer instead (Newcombe 1989:132).

There are many causes for the fuelwood problem, including the traditions ofits use and the absence of alternative fuels. The major reason for the lack of success in introducing alternative fuels is that wood has been regarded in most of Sub-Saharan Africa as a free good., taken largely from land to which everyone has the right of access (open-access land). As a result, a market for fuelwood has not developed in many countries despite its increasing scarcity. Even where fuelwood scarcity and high transport costs have created a market, the "producer price" of wood has remained below its replacement value because most supplies come from open-access forests. Market prices do not include the environmental costs of heavy fuelwood extraction. Alternative energy sources, such as kerosene, LPG, and electricity are costly; their cost more closely reflects their scarcity value since they are not obtainable from open-access sources. Despite dwindling forests and wood supplies, other fuels are not substituted in significant quantities, because the price of fuelwood is lower than that of alternative fuels. Investments in kerosene, LPG, and electricity supply systems must be made more efficient to make them more price competitive with fuelwood. Fuelwood prices, conversely, need to be increased. Chapter 8 suggests how this may be accomplished.

Logging

Commercial logging also takes a heavy toll—in large part because of inappropriate logging policies and practices. Commercial logging by itself is responsible for only about 10 to 20 percent of forest destruction in SubSaharan Africa, but it has been considerably more destructive in some countries, such as Cd'Ivoire It is, in fact, probably not so much the quantity logged but rather the procedures used that is the chief cause of forest destruction.

Logging practices are rarely monitored or controlled, and abusive logging practices are so common that they have become the norm (Repetto 1988a; Spears 19&8). Replanting is rare, because there is neither an incentive nor a requirement to do it Concession agreements usually require neither replanting nor maintenance of concession areas as a forest Most are also too short in duration to provide any inducement to the concessionaires to manage the concession areas for sustainable Iong-term multicycle production. Logging concessions are often awarded as a form of political patronage and abandoned once mined. Stumpage fees tend to be very low, further encouraging extensive and destructive logging (Grut, Gray and Egli 1991). In some cases, governments subsidize logging through tax and duty exemptions and through governmental financing of roads and infrastructure in forests. Subsidies provided to wood processing industries have the same effect Areas closer to ports appear to be most abused, with high transport costs being probably the most important factor protecting inland forests against logging in parts of Central Africa.

There is widespread agreement that logging in tropical forests, as now practiced, is not consistent with the sustainability of rain forest ecosystems. It has been argued that logging itself, if properly undertaken, need not necessarily destroy the forests However, recent surveys suggest that there are no sustained-yield forest management systems practiced on any sizeable scale in West and Central Africa (Goodland 199' :14; Besong and Wencus 1992). Even selective logging for certain species and/or trees of certain size disrupts these fragile ecosystems with their multitude of highly specialized life farms and of intricate multiple symbiotic relationships so severely that they will not survive intact. Although less directly linked to the nexus, population growth will stimulate more logging, with its significantly negative impact on the environment. Through the environmental impact may come declines in rainfall, increases in water runoff and, hence, declines in agricultural yields (see Chapter 2).

Logging almost invariably leads to a second — and more damaging —phase of forest destruction. Logging roads provide access for landhungry settlers into areas previously difficult to enter. Moving along and spreading out from the logging roads, landless or shifting cultivators rapidly take over logged-over forest areas, clear the remaining vegetation, and convert the land to agricultural uses usually at very low levels of productivity. This accelerates and expands the process of deforestation begun by the logging companies. Logging concessionaires ordinarily acquire rights to log from governments, ignoring the longstanding customary land and forest rights of forest dwellers. These rights, once eroded, are not respected by new settlers penetrating along the logging roads.

In virtually all countries of Sub-Saharan Africa, the institutions charged with managing and protecting national forest resources tend to be very weak. Forest guards and rangers often have neither the operating resources nor the training to monitor what is happening in the forest. They are even less equipped and prepared to regulate logging companies, deal with poachers, assist forest dwellers, and prevent encroachment by land-hungry settlers. These institutional weaknesses are so grave that fanner encroachment and logging occur on a significant scale even in many national parks. Forest services have little capacity to plan, to levy taxes, to undertake land use surveys, or to deal with land use disputes in forests (Besong and Wencus 1992).

The causes of the logging problem are related to those of the fuelwood problem. Forests have been widely regarded as reservoirs of free goods to be mined. Governments have shared in the bounty with private loggers through stumpage fees and taxes. However, once the forest disappears, the nontimber product; and the environmental services it provides disappear with it. The forest is disappearing fast.

Notes

1. In Sudan, for example, the parastatal Mechanized Farming Corporation has been awarding fifteen-year leases only to people who clear 85 percent of their assigned holdings in three years (Southgate 1990).

2. See Raintree (1987) for a number of detailed tree tenure studies in SubSaharan Africa.

3. There are exceptions—still found, for example, in southeastern Nigeria or western Sudan—where individuals and families may be given access to an amount of land but not to a specific plot. In such systems, where use rights for cultivation of seasonal crops rotate each year or after several years, individuals may not be keen on making long-terrn investments in land improvement (Migot-Adholla and others 1989).

Appendix to chapter 4

Statistical Analysis to Explain Intercountry Variations in Crop Yields

As in the case of the analysis of total fertility rates, two independent statistical investigations were undertaken to explain the cause of variation in yields per hectare of various crops, between countries and over time. (Both are described more fully in the Supplement.) Unfortunately, some of the relationships discussed in Chapter 4 could not be investigated due to lack of suitable data. However, limited testing may establish the plausibility of the hypotheses

· Incidence of drought will significantly affect crop yields.

· Crop yields should be higher where population is growing most rapidly relative to cultivated land. People begin to intensify agricultures cultivable area per person declines. Hence, statistical analysis should show an inverse relationship between area cultivated per person and crop yields (all other things being equal). However, the rate of growth in yields stimulated by declining availability of cultivable land per person will be significantly lower than the rate of population growth.

· Efforts to stimulate intensification (use of fertilizer, for example) will significantly accelerate the increase in crop yields beyond the growth rate stimulated by rising population density alone. This should be observed as higher yield growth rates in countries using more fertilizer (all other things being equal).

· Primary school of males and females, should facilitate farmer adoption of intensive farming techniques and therefore be associated with higher crop yields.

· Countries with more rapid degradation of their natural resource endowment, as reflected in higher rates of deforestation, should have lower crop yields, other things being equal

· Countries with a policy environment more accommodating for profitable market-oriented farming should have higher crop yields than countries with less conducive policies.

Pooled Cross-Country Time Series Analysis

The pooled cross-country time series analysis investigated the determinants of crop yields for cereals as a whole, as well as separately for rice, maize, sorghum, wheat, and cassava. The independent variables were drought, the nominal protection coefficient (representing the adequacy of agricultural policy), primary education, and cultivated area per capita. The higher the nominal protection coefficient, the higner is the farmgate price of the commodity relative to the world price. This is a proxy for the quality of the agricultural policy environment.

In summary, the following results were obtained (see the Supplement for details):

· Crop yields are negatively related to drought the coefficient on drought is negative for all crops and in all cases except for rice significant at the 10 percent level (this is the 2-tail significance test, meaning that there is a 90 percent probability that the coefficient is different from zero).

· Crop yields are positively related to good agricultural price policy the coefficient on the nominal protection coefficient is positive and in the case of cereals and sorghum significant at the 10 percent level. It shows no impact on cassava yields, however; this makes sense because cassava is a subsistence crop which is least affected by price policy.

· Crop yields are positively related to primary education the coefficient on primary education is positive, except for cassava and maize where it is highly insignificant. In the cases of rice and sorghum, it is significant at the 10 percent level.

· As hypothesized, yields are higher as the availability of cultivated land per capita declines: the coefficient on per capita land under annual and permanent crops is negative, except for cassava where it is highly insignificant. In the cases of rice and maize' it is significant at the 10 percent level. This means that for the crops which are most commercialized, the smaller the land holdings, the higher the yield (other things being equal).

· The for cassava are strikingly different from those for the cereal crops. Neither the nominal protection coefficient, nor primary education, nor per capita farm size affect cassava yields. Cassava is a subsistence crop and rarely traded on international markets.

Single-Observation Cross-Country Analysis

A separate analysis was undertaken of the causes for variations in crop yields using a different data set with single observations for each country. The main drawback of this approach is that it eliminates the time dimension from the analysis and that there are fewer observations. On the other hand, it allows a larger number of independent variables to be included. This analysis tested the statistical relationship between cereal yields (averages far 1984-1986) as the dependent variable, using as independent variables: cultivated area per person (average 1965-1987), fertilizer use per hectare m 1987/88 (fertilizer use remained fairly stable in the 1980s), percentage of the school-age population in primary school (average 1965-1987), the rate of deforestation in the 1980s, and the general "appropriateness" of agricultural policy during the period 1980 to 1987. Except for the rate of deforestation, the values for each variable were converted to their natural logarithm and a regression equation was fit to these data, the coefficients reported below therefore represent elasticities. Policy appropriateness is represented by a dummy variable having the value 1 for countries where policy is judged to have been conducive to profitable agriculture, and 0 where it is judged to have been inappropriate: Of the thirty-eight countries considered, twentyfour were judged to have pursued inappropriate policies, fourteen appropriate. This rating of countries is consistent with the categorization by the World Bank; it is, however, highly subjective. The role of women in agriculture and the effect of the land tenure situation could not be quantified and therefore were not tested in their impact on yields.

The equation, with the dependent variable being average cereal yields in 1984/86 (natural logarithm), is as follows:

Independent Variable

Coefficient t-statistic

2-Tail Significance Test

Constant

5.45

10.1

1%

Cultivated ha per persona

-0.33b

2.5

2%

Fertilizer use per haa

0.10b

1.7

10%

Primary school enrollment ratea

0.17b

1.2

24%

Deforestation rate

-0.05

0.9

39%

Agricultural policy dummy

0.30

1.9

7%

Adjusted R squared = 0.45




F Statistic = 7.0




a. Converted to natural logarithm.
b. Represents elasticity.

The equation explains about 45 percent of the differences in cereal yields among the thirty-eight countries; this is not as good as the pooled time series cross-country equation.

Consistent with the hypotheses and with the results from the pooled time series cross-country data, the smaller the cultivated area per person, the higher are cereal yields, all other things being equal. The coefficient (0.3) is identical using the two sets of data. The statistical relationship is highly significant, with a t-statistic of 2.5, and with a 2-tail significance test of 2 percent (indicating only a 2 percent probability that the coefficient is actually zero). It suggests that the pressure to intensify farming mounts with increasing population density on cultivated land; it is true even when the use of fertilizer and other modern inputs, the policy environment and primary school enrollment rates are held constant. This reflects farmers' ability to respond to rising population density with simple technological innovations. But, also consistent with the hypotheses, the coefficient is less than 1, suggesting that a decline in cultivated area per person (due to population growth) will only stimulate people to intensify farming at a rate of about one-third that of population growth itself. Historically, this is what happened. Cropland expanded at a rate of less than 1 percent per year, and yields increased on average by slightly more than I per year, giving an agricultural output growth of only about 2 percent per year for SSA as a whole for the 1965 1990 period.

A 1 percent increase in fertilizer intensity is associated with a 0.1 percent increase in cereal yields. The coefficient is significant statistically (2-tail test of 10 percent, indicating a 90 percent probability that the coefficient is not zero). Since fertilizer use is extremely low in SSA (averaging 85 grams per ha in 1987/88, compared to China, for example, where * is 2,360 g/ha), there is vast scope for increasing its use. This is also true for other modern tools and inputs, with which fertilizer use is highly correlated; given this correlation, the fertilizer variable also picks up the effect of the use of other modern inputs. Growth rates of fertilizer use (and other modem inputs) of 10-15 percent per year during the next decade are feasible. This would stimulate growth of cereal yields, according to this equation, by 1.0-1.5 percent per year.

A 1 percent increase in the share of prirnary school-age children enrolled in school is associated with an 0.17 percent increase in cereal yields. The statistical relationship is weak, but when added to the evidence cited in the text and the significance of this variable in the pooled cross-country time series tests, it suggests that better overall educational attainment has a positive impact or farm productivity This makes sense, since in most SSA countries the majority of the adult popuIation works in agriculture and associated activities.

The dummy variable representing agricultural policy adequacy is statistically significant in explaining cereal yield variation among countries. A better policy environment is associated wit., higher yields, all other things being equal This is consistent with the pooled cross-country time series analysis showing the significance of the nominal protection coefficient.

Consistent with the hypothesis, countries experiencing the most rapid deforestation have lower cereal yields, all other things being equal But the statistical relationship shows no significance The problem may be that deforestation is endogenous. The statistical tests summarized in Box 4A.2 suggest that deforestation itself is related to population density on cultivated land, intensity of fertilizer use, and agricultural policy. Therefore, when assesing the determinants of crop yields across countries, these other factors already pick up the impact of deforestation, thus leaving deforestation as such with a coefficient not significantly different from zero.

The above analysis also suggests the plausibility (though not the likelihood) of achieving 4 percent per year average growth of agriculture in SSA. This could occur from: more late or use per hectare facilitated by continued population growth (causing a 1 percent increase in annual output growth), 15 percent annual yield growth attributable to a 15 percent annual increase in the use of fertilizer (and of other modern inputs); and a rate of expansion in the cropped area of 05 percent per year This gives a total output growth rate of 35 percent per year An increase in the number of countries with appropriate agricultural policy and with primary school enrollment increasing at 2 percent per year should suffice to provide the additional 05 percent annual growth rate required to reach the postulated aggregate growth target. However, in the long run, as population growth slows, the scope for policy improvement narrows, and further expansion of cropped area becomes less feasible, sustaing 4 percent annual growth wilI become more difficult. It will depend increasingly on greater use of modern inputs and equipment, genetic improvements in crops and livestock, and improvements in people's educational attainment. Hence the importance of improved agricultural research and extension and of general education

Statistical Analysis to Explain Intercountry Variations in the Rate of Deforestation

The analysis in Chapter 4 suggests that deforestation is related positively to population pressure on cultivated land (the smaller the cultivated area per person, the higher the rate of deforestation), the rate of population growth (the higher population growth rate, the higher the rate of deforestation due to land clearing and fuelwood provision), and policies favorable to agriculture (the more profitable agriculture and logging, the more rapid the clearing of forests). It is negatively related to the use of modern farm inputs such as fertilizer (the greater the use of modern farm inputs, the lower the need to clear more land for farming). Open-access land tenure situations were also hypothesized to stimulate deforestation, but this cannot be quantified.

To test these hypotheses, regression analysis was undertaken with the rate of deforestation as the dependent variable. Two separate data sets were used, as described for the analysis of crop yields (seethe Supplement for details).

The nominal protection coefficient has no statistically significant relationship with deforestation, contrary to the hypothesis.

Using the data set with single observations per country, the dummy variable distinguishing countries with good agricultural policy (the variable has a value of 1) from those having poor policy (value 0) is nearly significant (2-tail test of 11 percent, or significance at the 89 percent level). The coefficient is positive, as hypothesized. The result is therefore ambiguous. Even if poor agricultural policy were to reduce the rate of conversion of forest to cropland, it would not be appropriate to pursue poor agricultural policy to conserve forest resources, because the objective of accelerating agricultural growth will override that of reducing the rate of deforestation in every country. However, this finding does suggest the need for mitigating actions to retard deforestation when agricultural policy is good. Land use planning will be important in this context.

The hypothesis that population pressure on cultivated area increases the rate of deforestation could not be confirmed. In the pooled cross country time series analysis, the relationship is not statistically significant In the simple cross-country sample, this variable had the expected negative coefficient (the smaller the cultivated area per person, the higher the rate of deforestation), but the significance level was very marginal (2-tail significance test of 15 percent). The result is therefore ambiguous and unconfirmed.

Drought proved to increase the rate of deforestation significantly.

As hypothesized, the use of modem farm inputs such as fertilizer is negatively related to the rate of deforestation. Intensifying agriculture slows the rate of deforestation This is likely to be the most important policy available to deal with this problem.