Preface

Over the past decade, the increasing power and reliability of microcomputers and the development of sophisticated software designed specifically for use with them has led to significant changes in the way that socioeconomic data are collected and analyzed. The venue of the computations has shifted from off-site mainframes, dependent on highly trained operators and significant capital investment in supporting equipment, to desktop and laptop computers, dependent only on the occasional availability of electricity. This means that it is now feasible to quickly transfer new statistical techniques between IFPRI and IFPRI’s collaborators in developing countries, that data manipulation costs of policy analysis have been substantially reduced, and that a new level of complexity and accuracy is now possible in the collection and analysis of household survey data in developing countries.

As with any new technology, however, there are substantial costs in time and money involved in learning the most efficient ways of using this new technology and then transmitting these lessons to others. This series, Microcomputers in Policy Research, represents IFPRI’s collective ongoing experience in adapting microcomputer technology for use in food policy analysis in developing countries. The papers in the series are primarily for the purpose of sharing these lessons with potential users in developing countries, although persons and institutions in developed countries may also find them useful. The series is designed to provide hands-on methods for resolving statistical and data-collection problems encountered in food policy research. In our opinion, examples provide the best and clearest form of instruction; therefore, examples—including actual software codes wherever relevant—are used extensively throughout this series.

This second book in the series, Strengthening Policy Analysis: Econometric Tests Using Microcomputer Software, by Lawrence Haddad, M. Daniel Westbrook, Daniel Driscoll, Ellen Payongayong, Joshua Rozen, and Melvyn Weeks, is a manual outlining how to conduct some fairly basic econometric tests and procedures to determine the robustness of the estimated parameters upon which policy decisions are frequently based. It is based on IFPRI experiences with cross-section econometric analysis over the past 10 years. The authors address a number of issues relating to the choice of model variables, the choice of estimation method, and the sensitivity of results to missing or extreme data values. Examples are provided throughout, using comparable programs from SPSS/PC+ä, SAS®, and GAUSS-386ä.

Howarth Bouis, Lawrence Haddad, and Stephen Vosti
Editors