Economic Imperialism or economics imperialism is an interesting phenomenon in social science. Economists and sometimes scholars originally from other disciplines have applied economic theory to that have traditionally been seen to belong to the domain of other sciences than economics. One scholar stands out as a prominent contributor to economics imperialism, namely Gary S. Becker, and therefore will focus on Becker''s work. I start my discussion with a historical outline of economics imperialism and an appraisal of the influence of Becker''s research. Then I analyze how economics imperialism can be characterized and what kind of view of the nature of scientific explanation it can be connected to, i.e. to unification. Moreover, I study problems related to preferences as explanatory factors, and also how preferences themselves can be explained. Finally, I discuss and evaluate the economics of crime, in particular the issue of the effectiveness of capital punishment in deterring murders. My work is directed to everyone interested in economics imperialism and its potential to unify social sciences, and especially to those interested in philosophy of social science.