19/09/2011: Highly Leveraged Banks' real impact on economy

An interesting paper from CEPR sheds some (largely theoretical) light on the real side of the current global financial crisis.

CEPR DP8576 titled "Financial-Friction Macroeconomics with Highly Leveraged Financial Institutions" by Sheung Kan Luk and David Vines (September 2011: available here) models the current crisis by adding "a highly-leveraged financial sector to the Ramsey model of economic growth". The paper shows that the presence of high leverage in financial sector "causes the economy to behave in a highly volatile manner" and thus exacerbate the macroeconomic effects of aggregate productivity shocks.

The model is based on the mainstream financial accelerator approach of Bernanke, Gertler and Gilchrist (BGG). The core BGG model assumes leveraged goods-producers are subjected to idiosyncratic productivity shocks, inducing them to borrow from a competitive financial sector.

Luk and Vines, by contrast, assume that "it is the financial institutions which are leveraged and subject to idiosyncratic productivity shocks." As the result of this, leveraged financial institutions "can only obtain their funds by paying an interest rate above the risk-free rate, and this risk premium is anti-cyclical [ in other words the premium is higher at the time of adverse productivity shock, i.e. during the recession], and so augments the effects of shocks."

Luk and Vines parameterise the model to US data under the assumption that "the leverage of the financial sector is two and a half times that of the goods-producers in the BGG model". The assumption is relatively robust for the current environment in the US. It is probably less robust in the case of the EU where financial sector leverage is likely to be higher in a number of countries due to:

1. Traditional over-reliance on debt financing of the banking sector
2. Lower rates of deleveraging in the banking sector than in the US, and
   
3. Greater deposits attrition during the crisis.
   

The study finds that the presence of leveraged financial institutions "causes a much more significant augmentation of aggregate productivity shocks than that which is found in the [traditional] BGG model."

In the nutshell, this provides a plausible explanation as to the channels through which financial sector funding and operational strategy risks (leading to higher leverage) transmit through to real economy. It also links more directly monetary policy to the real economy as well. Ben, keep that printing press running... nothing can possibly go wrong with negative interest rates, mate.