Control of interbank contagion under partial information

International audienceWe consider a stylized core-periphery financial network in which links lead to the creation of projects in the outside economy but make banks prone to contagion risk. The controller seeks to maximize, under budget constraints, the value of the financial system defined as the total amount of external projects. Under partial information on interbank links, revealed in conjunction with the spread of contagion, the optimal control problem is shown to become a Markov decision problem. We find the optimal intervention policy using dynamic programming. Our numerical results show that the value of the system depends on the connectivity in a non- monotonous way: it first increases with connectivity and then decreases with connectivity. The maximum value attained depends critically on the budget of the controller and the availability of an adapted intervention strategy. Moreover, we show that for highly connected systems, it is optimal to increase the rate of intervention in the peripheral banks rather than in core banks. Keywords: Systemic risk, Optimal control, Financial networks

Information acquisition and financial contagion.

This paper incorporates costly voluntary acquisition of information à la Nikitin and Smith (2007) [Nikitin, M., Smith, R.T., 2007. Information acquisition, coordination, and fundamentals in a financial crisis. Journal of Banking and Finance, in press, doi:10.1016/j.jbankfin.2007.04.031], in a framework similar to Allen and Gale (2000) [Allen, F., Gale, D., 2000. Financial contagion. Journal of Political Economy 108, 1–33], without relying on any unexpected shock to model contagion. In this framework, contagion and financial crises are the result of information gathering by depositors, weak fundamentals and an incomplete market structure of banks. It also shows how financial systems entering a recession can affect others with apparently stronger economic conditions (contagion). Finally, this is the first paper to investigate the effectiveness of the Contingent Credit Line procedures, introduced by the IMF at the end of the nineties, as a mechanism to prevent the propagation of crises.Central Bank; Contingent credit line; Financial contagion; Fundamentals; Verification equilibrium;

Bank Bailouts, International Linkages and Cooperation

Financial institutions are increasingly linked internationally. As a result, financial crisis and government intervention have stronger effects beyond borders. We provide a model of international contagion allowing for bank bailouts. While a social planner trades off tax distortions, liquidation losses and intra- and intercountry income inequality, in the noncooperative game between governments there are inefficiencies due to externalities, no burden sharing and free-riding. We show that, in absence of cooperation, stronger interbank linkages make government interests diverge, whereas cross-border asset holdings tend to align them. We analyze different forms of cooperation and their effects on global and national welfare.Portfolio choice, international transmission of shocks, monetary policy

Liquidity matters: Evidence from the Russian interbank market

We suggest an additional transmission channel of contagion on the interbank market - the liquidity channel. Examining the Russian banking sector, we and that the liquidity channel contributes significantly to understanding and predicting interbank market crises. Interbank market stability Granger causes the interbank market structure, while the opposite causality is rejected. This bolsters the view that the interbank market structure is endogenous. The results corroborate the thesis that prudential regulation at the individual bank level is insufficient to prevent systemic crises. We demonstrate that liquidity injections of a classical lender of last resort can effectively mitigate coordination failures on the interbank market both in theory and practice. Apparently, liquidity does matter.interbank market stability; contagion; liquidity channel; lender of last resort; Russia

Bank Bailouts, International Linkages and Cooperation

Financial institutions are increasingly linked internationally. As a result, financial crisis and government intervention have stronger effects beyond borders. We provide a model of international contagion allowing for bank bailouts. While a social planner trades off tax distortions, liquidation losses and intra- and inter-country income inequality, in the non-cooperative game between governments there are inefficiencies due to externalities, no burden sharing and free-riding. We show that, in absence of cooperation, stronger interbank linkages make government interests diverge, whereas cross-border asset holdings tend to align them. We analyze different forms of cooperation and their effects on global and national welfare.bailout, contagion, financial crisis, international institutional arrangements