The U.S. government guarantees a majority of residential mortgages to promote homeownership. This paper uses property-level data to estimate the effect of government guarantees on homeownership and other housing market outcomes, by exploiting variation of the conforming loan limits (CLLs) along county borders. We find that CLL changes had effects on government guarantees, house prices, house sales and construction activity, but find no robust effect on homeownership. The confidence intervals of our estimates suggest that one additional homeowner corresponds to an increase of government guarantees by at least $6 million. Therefore government guarantees could be considerably reduced with modest effects on homeownership. Our findings are relevant for housing finance reform plans that propose to lower the CLLs.

美国政府担保大多数住房抵押贷款以促进房屋所有权。本文利用财产水平的数据，通过利用沿县边界的合格贷款限额（CLL）的变化来估计政府担保对房屋所有权和其他住房市场成果的影响。我们发现，CLL的变化对政府担保，房价，房屋销售和建筑活动有影响，但对房屋所有权没有强大影响。我们的估计的置信区间表明，再增加一位房主，相当于将政府担保至少增加了600万美元。因此，可以大大减少政府担保，对房屋所有权产生适度影响。我们的发现与拟议降低CLL的住房金融改革计划有关。