This report describes important methodological issues involved in generating internationally comparable estimates of poverty. The special chapter, titled Comparing Poverty Across Countries: The Role of Purchasing Power Parities, also provides comparable rates of poverty using price data specific to the Asia and Pacific region, and, critically, to the poor. A major contribution of the report is to examine the sensitivity of poverty estimates to different methods for evaluating purchasing power parities (PPP). PPPs are conversion factors that ensure a common purchasing power over a given set of goods and services.