ورشکستگی سرایتی بانک ها در سیستم بانکداری آزاد

This paper develops a model of an unregulated banking system based around a private clearing house arrangement. Whilst such a system may dominate one with a public safety net in reducing moral hazard in lending and therefore the scope for individual bank insolvency, it also increases the likelihood of contagious bank failures following a systemic shock or an aggregate liquidity shortage.

An increasingly influential view on banking regulation holds that: (1) the proliferation of bank failures over the past two decades is caused to a large extent by ‘safety-net’ regulations put in place during the great depression to avert banking panics, and that (2) the only way to regain financial stability is to remove these protections and let the banking system operate with minimal regulatory intervention, (3) protection against systemic shocks can be provided more efficiently through private institutional arrangements such as clearing houses (see e.g. Calomiris, 1999). In this short paper we shall examine more closely the last point by considering equilibria in an unregulated banking sector, which may be vulnerable to contagious bank runs. We base our analysis on a model developed in Aghion et al. (1999).

The main point of this paper is to illustrate that a free banking system may not be immune to contagious bank runs. Moreover, the more efficient such a system is at reducing the potential insolvency of individual banks the more it exposes itself to contagious runs should there be a global liquidity shortage. In other words, the more efficient the system is at reducing the likelihood of an individual bank failure the bigger the amplification of a systemic shock through contagious bank runs. Clear implications for bank regulation cannot be drawn from these observations alone. A free banking system may dominate one with a public safety net if it reduces substantially the extent of moral hazard in lending. However, conditional on adopting a clearing house system it may be desirable to allow for sufficient risk taking by banks to ensure that the failure of an individual bank is not perceived by depositors as an unambiguous signal of a global liquidity crunch.