Household Risk Management and Optimal Mortgage Choice

Home mortgages are the most significant financial contract for many households. The form of this contract is correspondingly important. This paper studies the choice between fixed-rate (FRM) and adjustable-rate (ARM) mortgages. In an environment with uncertain inflation, nominal FRMs have risky real capital value whereas ARMs have safe capital value. However ARMs can greatly increase the short-term variability of required real interest payments. This is a serious disadvantage of ARMs for households who face borrowing constraints and have only a small buffer stock of financial assets. The paper uses numerical methods to solve a life-cycle model with risky labor income and borrowing constraints, under alternative assumptions about available mortgage contracts. Households with large mortgages, risky labor income, high risk aversion, and a low probability of moving are more likely to prefer nominal FRMs. The paper also considers inflation-indexed FRMs. These mortgages remove the wealth risk of nominal FRMs without incurring the income risk of ARMs, and therefore are a superior vehicle for household risk management. The paper finds that the welfare gains of mortgage indexation can be very large.