This chapter uses Uskali Mäki’s (2009) concepts of “good” and “bad” imperialism to investigate the “economics imperialism” thesis. If science expands by offering (a) consilience, and (b) epistemological and ontological unity – that is, it explains more phenomena with greater parsimony – then this is good scientific expansion. Economics imperialism is only bad if the methodology of economics expands outside its domain without increasing understanding in the above manners.