Chapter 5. Polarization

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 economic, a social, and a hybrid socioeconomic perspective. The chapter focuses largely on concepts and measurement, with only cursory overviews both of the empirical polarization literature and of the theoretical polarization/conflict literature. The chapter distinguishes five types of polarization: income polarization (where the polarizing variable of interest is any one-dimensional cardinal variable), income bipolarization (the extent to which a population is polarized across two separate groups lying on either side of an income median), social polarization (for cases in which variables of interest are qualitative or have no particular cardinal content), socioeconomic polarization (where some income groups split along social characteristics), and multidimensional polarization (where identity and distances/alienation are measured by several variables of interest).