Consumer Response to Changes in Credit Supply: Evidence from Credit Card Data

This paper utilizes a unique new data set on credit card accounts to analyze how people respond to changes in credit supply. The data consist of a panel of several hundred thousand individual credit card accounts followed monthly for 24-36 months, from several different card issuers, with associated credit bureau data. We estimate the dynamic effects of changes in the credit limit and in interest rates, and consider the ability of different models of consumption and saving to rationalize these effects. We find that increases in credit limits generate an immediate and significant rise in debt. This response is sharpest for people starting near their limit, providing evidence that liquidity constraints are binding. However, even people starting well below their limit significantly respond. We show this result is consistent with conventional models of precautionary savings. Nonetheless there are other results that conventional models cannot easily explain, such as the fact that many credit card borrowers simultaneously hold other low yielding assets. Unlike most other studies, we also find strong effects from changes in account-specific interest rates. Debt is particularly sensitive to large declines in interest rates, which can explain the widespread use of teaser rates. The long-run elasticity of debt to the interest rate is about -1.3. Less than half of this elasticity represents balance-switching across cards, with most reflecting net changes in total borrowing. Overall, the results imply that the consumer plays a potentially important role in the transmission of monetary policy and other credit shocks.