This chapter aims at recasting the traditional understanding of economics imperialism by proposing a historical narrative of the economics of discrimination. It defines two elements of economics imperialism: the crossing of established frontiers between approaches and disciplines, and the intention of substituting one approach for another. The chapter contextualizes Gary Becker's model of discrimination as imperialism "within economics" rather than towards other social sciences. By looking at the specific analytical tradition to which Becker belongs, the concept of economics imperialism is extended to encompass the role of smaller units of analysis than a discipline, such as research programs. The chapter characterizes Kenneth J. Arrow's statistical discrimination as a "humble" theoretical imperialism, calling for the complementarity of social sciences rather than for the superiority of economics. It argues that empirical measurements of discrimination in economics are a type of empirical imperialism essentially because these methods replace other social sciences in their contexts of expertise.