Financial regulation is harmonized across countries even though countries vary in their ability to bail-out their banking sector in the event of a crisis. This article addresses the question of whether countries with different fiscal capacity should optimally have different bank regulation, implemented—among other tools—through capital requirements—a question so far ignored by the theoretical banking literature. I show that countries with larger fiscal capacity should have lower ex ante minimum bank capital requirements, in an environment with endogenously incomplete markets and overinvestment due to “Too-Big-To-Fail” moral hazard and pecuniary externalities. I also show that, in addition to a minimum bank capital requirement, regulators in countries with strong “Too-Big-To-Fail” moral hazard should impose a limit on the liabilities pledged by financial institutions in a crisis state. This implies limits on put options/credit default swap contracts. Finally, I argue that the type of regulatory instrument used is crucial as to whether larger fiscal capacity implies more- or less-stringent bank regulation

How does the shadow banking system respond to changes in capital regulation of commercial banks? We propose a quantitative general equilibrium model with regulated and unregulated banks to study the unintended consequences of regulation. Tighter capital requirements for regulated banks cause higher convenience yield on debt of all banks, leading to higher shadow bank leverage and a larger shadow banking sector. At the same time, tighter regulation eliminates the subsidies to commercial banks from deposit insurance, reducing the competitive pressures on shadow banks to take risks. The net effect is a safer financial system with more shadow banking. Calibrating the model to data on financial institutions in the US, the optimal capital requirement is around 16

This article studies the effects of higher bank capital requirements. Using new firm-lender matched credit data from South Korea, we document that Basel III coincided with a 25% decline in credit from regulated banks, and an increase of similar magnitude from non-bank (shadow) lenders. We use our data to estimate the effect of capital requirements on bank credit, and the spillover effect of the reform on non-bank lending. We then build a general equilibrium model with heterogeneous banks and firms that replicates these micro estimates. We find that Basel III can account for most of the observed decrease in regulated bank lending and about three quarters of the increase in shadow lending. The latter is driven exclusively by general equilibrium effects of the reform

We study optimal enforcement in credit markets in which the only threat facing a defaulting borrower is restricted access to financial markets. We solve for the optimal level of exclusion, and link it to observed institutional arrangements. Regulation in this environment must accomplish two objectives. First, it must prevent borrowers from defaulting on one bank and transferring their resources to another bank. Second, and less obviously, it must give banks the incentive to make sizeable loans, and to honour their promises of future credit. We establish that the optimal regulation resembles observed laws governing default on debt. Moreover, if debtors have the right to a “fresh start” after bankruptcy then this must be balanced by enforceable provisions against fraudulent conveyance. Our optimal regulation is robust, in that it can be implemented in a way that does not require the regulator to have information about either the borrower or lender. Our results isolate the way in which specific institutions surrounding bankruptcy—namely rules governing asset garnishment and fraudulent conveyances—support loan markets in which borrowers have no collateral

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

I quantitatively analyse the macroeconomic impacts of raising capital requirements in a model in which heterogeneous firms may choose either intermediated or direct finance. Heterogeneous banks compete with other banks and the bond market, fund loans with insured deposits and costly equity (subject to a minimum capital-to-asset ratio), and monitor borrowers. I find that tighter capital requirements reduce costly bank failures while having only small effects on key macroeconomic aggregates, and that raising capital requirements above current levels can be welfare-improving. Three main forces give rise to these results. First, even though banks cut loan supply for a given level of net worth under a tighter capital requirement, in equilibrium banks’ net worth rises to dampen this effect. Second, intense competition from the non-bank sector disciplines banks’ lending responses to tighter regulation. Third, substitution by corporate firms offsets much of the decline in debt financing associated with tighter bank loan supply. As a corollary, almost all of the modest costs associated with tighter capital requirements are concentrated within the bank-dependent non-corporate sector

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

The recent unravelling of the Eurozone’s financial integration raised concerns about feedback loops between sovereign and banking insolvency. This article provides a theory of the feedback loop that allows for both domestic bailouts of the banking system and sovereign debt forgiveness by international creditors or solidarity by other countries. Our theory has important implications for the re-nationalization of sovereign debt, macroprudential regulation, and the rationale for banking unions

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