Bank capital regulations are intended to enhance financial stability in the long run, but may, in the meanwhile, involve costs for the real economy. To examine these costs we propose a narrative index of aggregate tightenings in regulatory US bank capital requirements from 1979 to 2008. Anticipation effects are explicitly taken into account and found to matter. In response to a tightening in capital requirements, banks temporarily reduce business and real estate lending, which temporarily lowers investment, consumption, housing activity and production. A decline in financial and macroeconomic risk helps sustain spending in the medium run. Monetary policy also cushions negative effects of capital requirement tightenings on the economy.