The Strategic Underreporting of Bank Risk

We show that banks significantly underreport the risk in their trading book when they have lower equity capital. Specifically, a decrease in a bank's equity capital results in substantially more violations of its self-reported risk levels in the following quarter. Underreporting is especially frequent during the critical periods of high systemic risk and for banks with larger trading operations. We exploit a discontinuity in the expected benefit of underreporting present in Basel regulations to provide further support for a causal link between capitalsaving incentives and underreporting. Overall, we show that banks' self-reported risk measures become least informative precisely when they matter the most.