The impact of China's economic fluctuations on nonperforming loans of state-owned and commercial banks: heterogeneity characteristics and transmission mechanisms

Based on China's macroeconomic data and banking non-performing loan data from 2010 to 2023, this paper studies the difference in the impact of economic fluctuations on the non-performing loans of state-owned banks and commercial banks and the transmission mechanism. The study selects GDP growth rate as the proxy variable of economic cycle, and constructs a time series model by combining the balance of non-performing loans, and reveals the long-term equilibrium relationship and short-term interaction characteristics between the two through cointegration analysis, causality test and dynamic response simulation. The results show that: first, economic fluctuations are significantly negatively correlated with non-performing loans. Second, state-owned banks are more sensitive to economic fluctuations than commercial banks due to policy-oriented credit expansion and industry-concentrated risks; third, external shocks lead to short-term surges in NPLs by exacerbating the pressure of corporate debt servicing and the lag of policy interventions, highlighting the dual impact of countercyclical regulation. The findings of the study provide theoretical support for optimizing differentiated bank supervision and improving risk mitigation tools, and have practical reference value for financial risk prevention and control in the period of economic transition.