We analyse a consumption-saving problem in which time-inconsistent preferences generate demand for commitment, but uncertainty about future consumption needs generates demand for flexibility. We characterize in a standard contracting framework the circumstances under which this combination is possible, in the sense that a commitment contract exists that implements the desired state-contingent consumption plan, thus offering both commitment and flexibility. The key condition that we identify is a preference reversal condition: high desired consumption today should be associated with low marginal utility at future dates. Moreover, there are conditions under which preference reversal naturally arises. The key insight of our article is that time-inconsistent preferences not only generate commitment problems, but also allow their possible solution, since the preferences of later selves can be exploited to punish overconsumption by earlier selves.

In most U.S. states, mortgage seniority follows time priority: older mortgages are paid first. This potentially impedes refinancing of senior mortgages because replacement mortgages are junior unless the existing junior lienholders consent to resubordination. We exploit legal variation across states to provide evidence that time priority reduces refinancing, especially of smaller mortgages (suggesting a significant fixed cost of obtaining resubordination) and of mortgages close to the conforming loan limit. On the contrary, we find evidence that time priority renders second mortgages more valuable to lenders, increasing the likelihood that a borrower obtains a second mortgage. Received May 20, 2013; editorial decision June 8, 2016 by Editor Laura Starks