Bank capital requirements are based on book values, which are slow to reflect losses. In this article, we develop a dynamic model of banks to study the interaction of regulation and delayed accounting. Our model explains four stylized facts: book and market values diverge during crises, the market-to-book ratio predicts future profitability, book leverage constraints rarely bind strictly even as market leverage fans out during crises, and banks delever gradually after net-worth shocks. We show how delayed accounting can allow the regulator to achieve better outcomes than immediate (mark-to-market) accounting. In an estimated version of the model, the optimal regulation couples faster loan-loss recognition with a modest relaxation of the book leverage constraint

Traditional banking is built on four pillars: small and medium enterprise lending, insured deposit taking, access to lender of last resort (LOLR), and prudential supervision. This article unveils the logic of the quadrilogy by showing that it emerges naturally as an equilibrium outcome in a game between banks and the government. A key insight is that regulation and public insurance services (LOLR, deposit insurance) are complementary. The model also shows how prudential regulation must adjust to the emergence of shadow banking and rationalizes structural remedies to counter bogus liquidity hoarding and financial contagion: ring-fencing between regulated and shadow banking and the sharing of liquidity in centralized platforms

How should macroprudential policy be designed when policymakers also have access to liquidity provision tools to manage crises? We show in a tractable model of systemic banking risk that there are three factors at play: first, ex post liquidity provision mitigates financial crises, and this reduces the need for macroprudential policy. In the extreme, if liquidity provision is untargeted and costless or if it completely forestalls crises by credible out-of-equilibrium lending-of-last-resort, there is no role left for macroprudential regulation. Second, however, macroprudential policy needs to consider the ex ante incentive effects of targeted liquidity provision. Third, if shadow banking reduces the effectiveness of macroprudential instruments, it is optimal to commit to less generous liquidity provision as a second-best substitute for macroprudential policy

Should regulators encourage the migration of trade from over-the-counter (OTC) to centralized markets? To address this question, we study a model in which banks make costly decisions to participate in an OTC market, a centralized market, or both markets at the same time. Banks differ in their ability to take large positions, what we call their trading capacity. In equilibrium, intermediate-capacity banks find it optimal to participate in the centralized market. In contrast, low- and high-capacity banks find it optimal to participate in the OTC market, due to an endogenous complementarity. Namely, low-capacity banks receive worse terms of trade than in the centralized market but better risk sharing, thanks to the intermediation services offered by high-capacity banks. High-capacity banks receive worse risk sharing than in the centralized market, but profit from the provision of intermediation services to low-capacity banks. While the social optimum has qualitatively similar participation patterns, it prescribes that more customers migrate to the centralized market, and that more dealers enter the OTC market