Monetary Policy Leverage And Bank Risk Taking

We provide a theoretical foundation for the claim that prolonged periods of easy monetary conditions increase bank risk taking. The net effect of a monetary policy change on bank monitoring (an inverse measure of risk taking) depends on the balance of three forces: interest rate pass-through, risk shifting, and leverage. When banks can adjust their capital structures, a monetary easing leads to greater leverage and lower monitoring. However, if a bank's capital structure is fixed, the balance depends on the degree of bank capitalization: when facing a policy rate cut, well capitalized banks decrease monitoring, while highly levered banks increase it. Further, the balance of these effects depends on the structure and contestability of the banking industry, and is therefore likely to vary across countries and over time.

We present evidence of a risk-taking channel of monetary policy for the U.S. banking system. We use confidential data on the internal ratings of U.S. banks on loans to businesses over the period 1997 to 2011 from the Federal Reserve’s survey of terms of business lending. We find that ex-ante risk taking by banks (as measured by the risk rating of the bank’s loan portfolio) is negatively associated with increases in short-term policy interest rates. This relationship is less pronounced for banks with relatively low capital or during periods when banks’ capital erodes, such as episodes of financial and economic distress. These results contribute to the ongoing debate on the role of monetary policy in financial stability and suggest that monetary policy has a bearing on the riskiness of banks and financial stability more generally.

We present evidence of a risk-taking channel of monetary policy for the U.S. banking system. We use confidential data on banks' internal ratings on loans to businesses over the period 1997 to 2011 from the Federal Reserve's survey of terms of business lending. We find that ex-ante risk taking by banks (measured by the risk rating of new loans) is negatively associated with increases in short-term interest rates. This relationship is more pronounced in regions that are less in sync with the nationwide business cycle, and less pronounced for banks with relatively low capital or during periods of financial distress.

This paper contributes to the current debate on what role financial stability considerations should play in monetary policy decision and how best to integrate macro-prudential and monetary policy frameworks. The paper broadly supports the view that monetary policy easing induces greater risk-taking by banks but also shows that the relationship between real interest rates and banking risk is more complex. Ultimately, it depends on how much skin in the game banks have. The central message of the paper is broadly complementary to those in the recent MCM board paper “Central Banking Lessons from the Crisis.”

This paper develops a model to assess how monetary policy rates affect bank risk-taking. In the model, a reduction in the risk-free rate increases lending profitability by reducing funding costs and increasing the surplus the monopolistic bank extracts from borrowers. Under limited liability, this increased profitability affects only upside returns, inducing the bank to take excessive leverage and hence risk. Excessive risk-taking increases as the interest rate decreases. At a broader level, the model illustrates how a benign macroeconomic environment can lead to excessive risk-taking, and thus it highlights a role for macroprudential regulation.

This paper develops a dynamic bank model to show that expansionary monetary shocks can increase bank risk-taking through higher leverage. Lower monetary policy rates increase lending profitability which can encourage the bank to take more leverage to finance new loans. In the presence of limited liability, the increase in leverage and risk can be excessive. However, the relationship can be non-monotonic. When the bank cannot issue equity, a small reduction in monetary policy rates can reduce excessive risk-taking, whereas a large one can increase it. When the bank can issue equity but adjusting dividends is costly, lower monetary policy rates always induce excessive risk-taking and the effect is quite persistent. In this model, capital requirements work better than loan-to-value caps in reducing excessive risk taking because they are closer to the source of the distortion.

Traditional theory suggests that more profitable banks should have lower risk-taking incentives. Then why did many profitable banks choose to invest in untested financial instruments before the crisis, realizing significant losses? We attempt to reconcile theory and evidence. In our setup, banks are endowed with a fixed core business. They take risk by levering up to engage in risky ‘side activities’(such as market-based investments) alongside the core business. A more profitable core business allows a bank to borrow more and take side risks on a larger scale, offsetting lower incentives to take risk of given size. Consequently, more profitable banks may have higher risk-taking incentives. The framework is consistent with cross-sectional patterns of bank risk-taking in the run up to the recent financial crisis.

How does monetary policy impact upon macroprudential regulation? This paper models monetary policy's transmission to bank risk taking, and its interaction with a regulator's optimization problem. The regulator uses its macroprudential tool, a leverage ratio, to maintain financial stability, while taking account of the impact on credit provision. A change in the monetary policy rate tilts the regulator's entire trade-off. We show that the regulator allows interest rate changes to partly "pass through" to bank soundness by not neutralizing the risk-taking channel of monetary policy. Thus, monetary policy affects financial stability, even in the presence of macroprudential regulation.