Financial crises and liquidity shocks a bank-run perspective

In contrast with the financial multiplier literature, this note explores a case in which the shock triggering a financial crisis stems from the financial sector itself; it is not a shock stemming from the real sector which gets amplified by, say, agency problems. The basic intuition is provided by the bank-run literature of the Diamond and Dybvig (1983) variety. Financial development is modeled as a mechanism that endows real assets (e.g., land and capital) with liquidity. However, liquidity can be impaired by shocks that are equivalent to a bank run. Liquidity creation enhances real asset prices, while a liquidity crunch generates asset price collapse. This bubble-looking episode is not driven by standard fundamentals, although it is fully in line with rationality. In this context, devoid of other frictions like price stickiness, the note examines the effect of monetary policy in the absence of nominal rigidities. It shows that preventing price deflation is not enough to offset relative (to output) asset price meltdown, but lower policy interest rates increase relative asset prices and steady-state output. Moreover, in the neighborhood of a first-best capital allocation, an increase in the liquidity of capital may lower the welfare of the representative individual, even if the higher liquidity of capital is sustainable and, hence, not destroyed by future crash – illustrating the possibility of “excessive” financial innovation. An extension of the basic model supports the conjecture that low policy interest rates may have given further incentives to the development of “shadow banking.”