Consumption and Debt Dynamics with (Rarely Binding) Borrowing Constraints

This paper examines consumption and savings dynamics in a standard model of incomplete markets. Existence of equilibrium requires the imposition of exogenous debt limits but these are often ignored because of the computational difficulties that arise in models with occasionally binding constraints. I claim that borrowing constraints have a significant qualitative and quantitative effect on equilibrium allocations even if they rarely bind. Contrary to standard results in the literature, debt exhibits mean reversion, consumption responds strongly to idiosyncratic income shocks and interest rates respond to both aggregate and idiosyncratic innovations in income. The implication is that market incompleteness can generate much lower consumption correlations than was previously thought.