Abstract
Macroeconomic traditions disagree on the policies needed for the economy to properly function and how to assess them. In this paper, we contend that these disagreements originate from the social ontological commitments of a theory. The ontology of money underlines these disagreements between Modern Monetary Theory (MMT) and mainstream economics. First, we assess MMT’s ontology of money. Next, we identify MMT’s normative commitments and classify MMT’s ontology as a taxonomic definition with thick concepts. Finally, we offer reasons why MMT's ontology of money leads to rivalries with other economic traditions. We argue disagreements on policy are expected, given the ontological differences elaborated.