How Do Banks Respond to Regulatory Capital Requirements?
Abstract
Banks allocate their portfolios across different types of loans and securities. Changes in capital requirements affect multiple assets’ regulatory penalties simultaneously. Although a large literature finds that stronger capital requirements reduce lending, these bank-level studies generally estimate an aggregate lending elasticity that combines asset-level elasticities with portfolio substitution. Analyzing policies that change the regulatory penalties of individual assets, rather than of individual banks (e.g., raising the risk weight on Treasuries), requires separating these quantities. I develop a new structural framework and empirical method to separate asset-level supply elasticities from portfolio substitution by using changes in bank-level requirements that change multiple assets’ regulatory penalties simultaneously subject to a portfolio adding-up constraint. My method recovers a positive supply elasticity for every asset category and finds that banks’ securities holdings respond more to regulatory costs than loans do. Its predictions match out-of-sample bank portfolio responses to changes in capital regulation. Applying these elasticities to post-crisis capital requirements, I ask whether stronger capital regulation explains banks’ move away from lending since the financial crisis. I show that capital requirements account for a relatively small share of large banks’ shift from lending to securities since 2011.
