The GSE implicit subsidy and the value of government ambiguity

The housing-related government-sponsored enterprises Fannie Mae and Freddie Mac (the "GSEs") have an ambiguous relationship with the federal government. Most purchasers of the GSEs' debt securities believe that this debt is implicitly backed by the U.S. government despite the lack of a legal basis for such a belief. In this paper, I estimate how much GSE shareholders gain from this ambiguous government relationship. I find that (1) the government's ambiguous relationship with Fannie Mae and Freddie Mac imparts a substantial implicit subsidy to GSE shareholders, (2) the implicit government subsidy accounts for much of the GSEs' market value, and (3) the GSEs would hold far fewer of their mortgage-backed securities in portfolio and their capital-to-asset ratios would be higher if they were purely private.