Research On The Banking Systemic Risk Control From The Perspective Of Interbank Exposure Network Optimization

Since the financial crisis in 2008,countries around the world and international regulatory agencies have stepped up their supervision of banks in order to prevent the occurrence of banking systemic risk.The interbank capital lending relationship after the banks’ rational decision forms the interbank exposure network,which is co-evolving with the banking systemic risk.By influencing the bank’s decision-making behavior of capital borrowing(such as taxation),the resulting interbank exposure network can be optimized and the risk of bank default infection on the network can be minimized,thereby the goal of controlling banking systemic risks can be achieved.First,this paper gives the formation and evolution mechanism of the interbank exposure network under the rational decision-making of interbank capital borrowers and lenders,and then constructs the default contagion model on the interbank exposure network.Finally,this paper studies the impact of the Systemic Risk Taxes on banking systemic risk from the perspective of theoretical analysis and numerical simulation.In the actual interbank market,there are differences in the size of banks’ assets,and loans between banks of the same type are more frequent.Based on this,this paper innovatively brings the bank’s asset size preference into the selection mechanism of lending objects,forming a more realistic interbank exposure network.The results of theoretical analysis show that there may be multiple rational decision-making results without the intervention of regulatory agencies,but the banking systemic risk from the resulting network is generally high;the Systemic Risk Taxes can significantly reduce the banking systemic risk of the network without sacrificing the amount of borrowed capital.The numerical simulation results of the interbank market with different bank asset size distributions further verify the theoretical analysis conclusions.Specifically,the tax intervention significantly reduces the number of bank borrowers,the average clustering coefficient and spectral radius of the interbank exposure network;the interbank market with evenly distributed bank assets has lower systemic risk and greater volatility without intervention;there is no significant difference in systemic risk across the interbank market for different bank’s asset sizes with the Systemic Risk Taxes.This paper integrates the bank’s asset size preference into the bank lending objects selection mechanism,and the obtained interbank exposure network is more realistic.This paper also finds that the method of tax intervention can be applied to the interbank market with different bank asset size distributions,which improves the practical value of this method.The research results provide a new perspective for banking systemic risk management.