  Our knowledge about the evolution of guarantee network in downturn period is
limited due to the lack of comprehensive data of the whole credit system. Here
we analyze the dynamic Chinese guarantee network constructed from a
comprehensive bank loan dataset that accounts for nearly 80% total loans in
China, during 01/2007-03/2012. The results show that, first, during the
2007-2008 global financial crisis, the guarantee network became smaller, less
connected and more stable because of many bankruptcies; second, the stimulus
program encouraged mutual guarantee behaviors, resulting in highly reciprocal
and fragile network structure; third, the following monetary policy adjustment
enhanced the resilience of the guarantee network by reducing mutual guarantees.
Interestingly, our work reveals that the financial crisis made the network more
resilient, and conversely, the government bailout degenerated network
resilience. These counterintuitive findings can provide new insight into the
resilience of real-world credit system under external shocks or rescues.
