Explaining the Housing Bubble
Adam J. Levitin
Georgetown University Law Center
Susan M. Wachter
University of Pennsylvania – The Wharton School – Real Estate Department
August 31, 2010
Georgetown Law and Economics Research Paper No. 1669401
Georgetown Public Law Research Paper No. 1669401
U of Penn, Inst for Law & Econ Research Paper Forthcoming
There is little consensus as to the cause of the housing bubble that precipitated the financial crisis of 2008. Numerous explanations exist: misguided monetary policy; government policies encouraging affordable homeownership; irrational consumer expectations of rising housing prices; inelastic housing supply. None of these explanations, however, is capable of fully explaining the housing bubble, much less the parallel commercial real estate bubble.
This Article posits a new explanation for the housing bubble. It demonstrates that the bubble was a supply-side phenomenon, attributable to an excess of mispriced mortgage finance: mortgage finance spreads declined and volume increased, even as risk increased, a confluence attributable only to an oversupply of mortgage finance.
The mortgage finance supply glut occurred because markets failed to price risk correctly due to the complexity and heterogeneity of the private-label mortgage-backed securities (MBS) that began to dominate the market in 2004. The rise of private-label MBS exacerbated informational asymmetries between the financial institutions that intermediate mortgage finance and MBS investors. The result was overinvestment in MBS that boosted the financial intermediaries’ profits and enabled borrowers to bid up housing prices.
Despite mortgage securitization’s inherent informational asymmetries, it is critical for the continued availability of the long-term fixed-rate mortgage, which has been the bedrock of American homeownership since the Depression. The benefits of securitization, therefore, must be reconciled with the need for economic stability. The Article proposes the standardization of MBS to reduce complexity and heterogeneity in order to rebuild a sustainable, stable housing finance market based around the long-term fixed-rate mortgage.