ABSTRACT
Inequality is a broad and multifaceted concept. It poses theoretical and empirical questions about how it should be modeled and measured. In general, we talk about inequality when the distribution of a particular resource in a population deviates from a desired condition of equity. Defining inequality in a way that allows one for precise measurement, however, is far from straightforward. This chapter draws attention to the interplay between models and measurement in the scientific investigation of income inequality. In particular, the first part of this chapter introduces two standard models of inequality, the Lorenz curve and the Gini index, and shows how they can be used to elaborate empirical data on income inequality. The second part reviews contrasting findings about global income inequality and argues that such findings are reconcilable once interpreted in light of the distinct representations of inequality underlying alternative measurement methods.
