This document is a publication of the "Poverty and Food Insecurity Mapping Project" (GCP/INT/761/NOR), which is funded by the Government of Norway and implemented jointly by UNEP-GRID-Arendal, the CGIAR Centers and FAO. The author would like to thank Fabio Pittaluga, Paul Winters, Patrick Webb, David Bigman, Nicholas Minot, Andrew Nelson, Calogero Carletto, Raffaella Siano, Leslie Lipper, Barbara Huddleston, Claudia Heberlein, Ergin Ataman, Glenn Hyman, Changchui He, Freddy Nachtergaele and Tim Kelley for detailed comments and suggestions on an earlier draft of this paper. Gregoire Leclerc and Uwe Deichmann kindly provided maps. Thanks are also due to participants at the workshop on poverty mapping in Amsterdam sponsored by the World Bank in October 2001 for comments and discussion, and to the many other individuals who responded to entreaties for information. Special thanks are due to Marina Pelaghias and Chrissi Smith Redfern for putting together the printed version of this paper and Omar Iglesias and Marco Bloise for the cover design. The content is exclusively the responsibility of the author, not that of FAO.