This chapter reviews the long-run developments in the distribution of personal income and wealth. It also discusses suggested explanations for the observed patterns. We try to answer questions such as: What do we know, and how do we know, about the distribution of income and wealth over time?...

This chapter reviews the basic conceptual foundations for the measurement of polarization, the origins of those foundations, how polarization is distinct from inequality and other ways of considering distances and differences across individuals, and how polarization can be measured in an...