Data Sources for the Study of Economic Inequality

Measuring economic inequality requires sound data on individuals’ resources. The collection and storage of this information involves methodological and definitional choices that have been the subject of much debate, as they affect the possibilities for the subsequent analysis and the interpretation of the results. This chapter aims to answer the question “where to look for data on economic inequality?” by presenting the different types of sources available and highlighting the definitions considered and methodologies used. A discussion of the advantages and disadvantages of each source is provided, together with a detailed description of the main survey databases. Moreover, data used to study inequality need to satisfy multiple requirements in terms of quality. In particular, non-sampling errors can seriously affect data and synthetic information derived from all types of sources. Typologies of non-sampling errors and methods to prevent and reduce their impact are discussed. Finally, secondary databases containing measures of economic inequality are described and some examples of studies of multidimensional inequality that are based on inequality data sources are reported.