Constructing Comparable Global Poverty Trends

Overview & Synopsis

Countries frequently revise how they measure income or consumption due to changes in data collection and questionnaire design. These changes create comparability breaks in poverty trends over time. This paper develops three methods to create global, regional, and country-level poverty trends that are comparable within countries over time. It does so by using national accounts growth to bridge non-comparable sequences. Accounting for comparability breaks creates large differences in some country-level poverty trends, but the global extreme poverty trend built from these comparable poverty series remains largely unchanged.