Is it possible to avoid a lemon? Reflections on choosing a poverty mapping method

Poverty and food security in most countries are highly heterogeneous phenomena. Both types and depth of poverty, measured in a variety of ways, vary between and within countries, regions or other geographic and administrative units. Poverty mapping in all its various forms involves techniques which permit sufficient disaggregation of a poverty measure to local administrative levels or small geographical units. All poverty mapping techniques imply alternative schemes for weighting a particular poverty index, and may imply alternative rankings by poverty of the chosen unit. The methodologies utilized are diverse, from participatory poverty profiles to sophisticated econometric techniques, and most are under continuing development. Each of these has different data requirements and implementation costs, and different advantages and disadvantages in their use. The themes of statistical error and possible bias are key issues in poverty mapping. The purpose of this paper is to discuss the relevance of and options in poverty and food security mapping for analysis and policy design and implementation in the rural sector of developing countries. We present and compare a large selection of the alternative poverty and food security mapping methodologies in use, in order to provide some guidance as to the possibilities and appropriateness of these methodologies for different policy applications. We do this by studying in detail a number of applications of poverty mapping to policy questions.