Benjamin D Nelson

Simple Banking: Profitability and the Yield Curve

How does bank profitability vary with interest rates? We present a model of a monopolistically competitive bank subject to repricing frictions, and test the model’s predictions using a unique panel data set on UK banks. We find evidence that large banks retain a residual exposure to interest rates, even after accounting for hedging activity operating through the trading book. In the long run, both level and slope of the yield curve contribute positively to profitability. In the short run, however, increases in market rates compress interest margins, consistent with the presence of non negligible loan pricing frictions.

Shadow Banks and Macroeconomic Instability

We develop a macroeconomic model in which commercial banks can offload risky loans to a ‘shadow’ banking sector, and financial intermediaries trade in securitised assets. We analyse the responses of aggregate activity, credit supply and credit spreads to business cycle and financial shocks. We find that: interactions and spillover effects between financial institutions affect credit dynamics; high leverage in the shadow banking system makes the economy excessively vulnerable to aggregate disturbances; and following a financial shock, stabilisation policy aimed solely at the securitisation markets is relatively ineffective.

Reputation, Risk-Taking and Macroprudential Policy

This paper examines the role of macroprudential capital requirements in preventing inefficient credit booms in a model with reputational externalities. Unprofitable banks have strong incentives to invest in risky assets and generate inefficient credit booms when macroeconomic fundamentals are good in order to signal high ability. We show that across-the-system countercyclical capital requirements that deter credit booms are constrained optimal when fundamentals are within an intermediate range. We also show that when fundamentals are deteriorating, a public announcement of that fact can itself play a powerful role in preventing inefficient credit booms, providing an additional channel through which macroprudential policies can improve outcomes.

Do contractionary monetary policy shocks expand shadow banking

Using vector autoregressive models with either constant or time-varying parameters and stochastic volatility for the United States, we find that a contractionary monetary policy shock has a persistent negative impact on the asset growth of commercial banks, but increases the asset growth of shadow banks and securitisation activity. To explain this ‘waterbed’ effect, we propose a standard New Keynesian model featuring both commercial and shadow banking, and we show that the model comes close to explaining the empirical results. Our findings cast doubt on the idea that monetary policy can usefully ‘get in all the cracks’ of the financial sector in a uniform way.

Bank Leverage, Credit Traps and Credit Policies

We construct an overlapping generations macroeconomic model with which to study the causes, consequences and remedies to ‘credit traps’ — prolonged periods of stagnant real activity accompanied by low productivity, financial sector undercapitalisation, and the misallocation of credit. In our model, credit traps arise when shocks to bank equity capital tighten banks’ borrowing constraints, causing them to allocate credit to easily collateralisable but low productivity projects. Low productivity weakens bank capital generation, reinforcing tight borrowing constraints, sustaining the credit trap steady state. We use the model to study policy options, both ex ante(avoiding credit traps) and ex post (escaping them). Ex ante, restrictions on bank leverage can help to enhance the economy’s resilience to the shocks that can cause credit traps. Further, a policymaker focused on maximising the economy’s resilience to credit traps would set leverage countercyclically, allowing an expansion of leverage in minor downturns and reducing leverage in upswings. However, ex post, relaxing a leverage cap will not help escape the trap. Instead, a range of unconventional policies are needed. We study publicly intermediated lending, discount window lending, and recapitalisation, and compare the efficacy of these policies under different conditions.