Bank Capital Standards for Market Risk: A Welfare Analysis

We propose a simple model that is suitable for evaluating alternativebank capital regulatory proposals for market risk. Our modelformalizes the conflict between bank objectives and regulatorygoals. Banks' decisions represent a tension between their desireto exploit the deposit-insurance put option and their desireto preserve franchise value. Regulators seek to balance thesocial value of deposits in mediating transactions against thedeadweight costs of failure resolution. Our social welfare criterionis standard: a weighted average agents' utilities. We demonstrate that banks do not incrementally alter their portfoliorisk as the economic environment changes. Rather, banks eitherchoose the minimal feasible risk or the maximal feasible risk.This pattern, in turn, drives regulatory decisions: The firstgoal of the regulator is to induce banks to choose the minimalrisk level. For all nontrivial cases, unregulated banks failto choose the first-best allocations. Traditional ex-ante capitalrequirements can induce banks to choose the socially-optimallevel of portfolio risk, but the required capital is often inefficientlyhigh. In contrast, variants of the Federal Reserve Board's precommitmentproposal imply far smaller efficiency losses, and achieve allocationsat or nearthe first-best for most reasonable model specifications.The ex-post penalties required for the optimal implementationof precommitment are not excessively large. The welfare gainsfrom precommitment are even higher when the precommitment penaltyfunction is precluded from sending banks into default. We concludethat state-contingent regulatory mechanisms, of which the precommitmentapproach is an example, offer the possibility of substantialgains in regulatory efficiency, relative to traditional statenon-contingent regulation.     

Measuring systemic risk: A risk management approach

This paper proposes a new method to measure and monitor the risk in a banking system. Standard tools that regulators require banks to use for their internal risk management are applied at the level of the banking system to measure the risk of a regulator’s portfolio. Using a sample of international banks from 1988 until 2002, I estimate the dynamics and correlations between bank asset portfolios. To obtain measures for the risk of a regulator’s portfolio, I model the individual liabilities that the regulator has to each bank as contingent claims on the bank’s assets. The portfolio aspect of the regulator’s liability is explicitly considered and the methodology allows a comparison of sub-samples from different countries. Correlations, bank asset volatility, and bank capitalization increase for North American and somewhat for European banks, while Japanese banks face deteriorating capital levels. In the sample period, the North American banking system gains stability while the Japanese banking sector becomes more fragile. The expected future liability of the regulator varies substantially over time and is especially high during the Asian crisis starting in 1997. Further analysis shows that the Japanese banks contribute most to the volatility of the regulator’s liability at that time. Larger and more profitable banks have lower systemic risk and additional equity capital reduces systemic risk only for banks that are constrained by regulatory capital requirements.     

The Impact of Capital-Based Regulation on Bank Risk-Taking

In this paper we model the dynamic portfolio choice problem facing banks, calibrate the model using empirical data from the banking industry for 1984–1993, and assess quantitatively the impact of recent regulatory developments related to bank capital. The model implies a U-shaped relationship between capital and risk-taking: As a bank's capital increases it first takes less risk, then more risk. A deposit insurance premium surcharge on undercapitalized banks induces them to take more risk. An increased capital requirement, whether flat or risk-based, tends to induce more risk-taking by ex-ante well-capitalized banks that comply with the new standard. Journal of Economic Literature Classification Numbers: G20, G28.     

A Prudential Paradox: The Signal in (Not) Restricting Bank Dividends

By restricting dividends in the weakest banks, prudential regulators counterintuitively induce more capital payouts in marginal banks. The potential for bank runs exacerbates the incentive to signal strength through dividend payments. Regulatory restrictions on those payments can be used to achieve the first-best outcome, but only if the prevailing capital requirements are sufficiently high. In a crisis, the optimal dividend policy is more restrictive, since it allows the weak but solvent banks to pool with the strong. Finally, we show that the optimal release of regulatory bank information depends critically on the regulator's information and dividend restriction policies.     

Why do banks choose to finance with equity?

A majority of U.S. banks between 1973 and 2012 held equity capital significantly beyond the required minimum. We study the risk-return tradeoff in connection with a bank’s capital structure, and identify several new significant market factors that drive the level of equity capital in banks. During normal growth periods, bank leverage is negatively related to a level of competition and loan portfolio diversification, while high bank leverage is associated with low past liquidity. During recessions and expansions, the roles of those factors change following distortions in risk-return tradeoff. In distress, when banks approach regulatory capital requirements, market determinants of book leverage lose their significance; however, leverage does not decrease until a bank is within 1% of the minimal capital threshold.     

A guide to choosing absolute bank capital requirements

Resampling implementation of a stress-scenario approach to estimating portfolio default loss distributions is proposed as the basis for estimates of the appropriate absolute level of economic capital allocations for portfolio credit risk. Estimates are presented for stress scenarios of varying severity and implications of different time horizons are analyzed. Results for a numeraire portfolio are quite sensitive to such variations. Although the analysis is framed in terms of recent proposals to revise regulatory capital requirements for banks, the arguments and results are also relevant for bankers making capital structure decisions.     

The dark side of liquidity creation: Leverage and systemic risk

We consider a model in which the threat of bank liquidations by creditors as well as equity-based compensation incentives both discipline bankers, but with different consequences. Greater use of equity leads to lower ex-ante bank liquidity, whereas greater use of debt leads to a higher probability of inefficient bank liquidation. The bank's privately-optimal capital structure trades off these two costs. With uncertainty about aggregate risk, bank creditors learn from other banks’ liquidation decisions. Such inference can lead to contagious liquidations, some of which are inefficient; this is a negative externality that is ignored in privately-optimal bank capital structures. Thus, under plausible conditions, banks choose excessive leverage relative to the socially optimal level, providing a rationale for bank capital regulation. While a blanket regulatory forbearance policy can eliminate contagion, it also eliminates all market discipline. However, a regulator generating its own information about aggregate risk, rather than relying on market signals, can restore efficiency and market discipline by intervening selectively.     

The implications of the new capital adequacy rules for portfolio management of credit assets

Over the past several years, there has been an extensive discussion among practitioners and academics about whether and how a portfolio management approach could help banks to better manage risk capital and create shareholder value. In this article, the authors argue that there are four key drivers which require banks to move from a transactional to a more portfolio management like approach when managing credit assets. These are: structural changes in the credit markets, inefficiencies of risk transfer in lending markets, ballooning debt levels in the US, and the proposed changes for capital adequacy. The authors see the latter not as a one-time change in capital adequacy rules, but more as a first step towards full convergence between risk capital and regulatory capital for credit risk. These changes require banks to accelerate their efforts to build first class portfolio management skills and capabilities. Achieving best practice credit portfolio management is rewarded with attractive opportunities for shareholder value creation and enables bank to successfully compete going forward.     

Capital, Portfolio, and Growth: Bank Behavior Under Risk-Based Capital Guidelines

This paper examines banks' capital, portfolio and growth decisions from 1986 to 1995, when risk-based capital guidelines were proposed and implemented. Overall, we observe complementarity between equity financing and risk. We find no systematic differences in pre- and postregulation behavior consistent with banks reacting to risk-based capital standards implementation. We do find significant differences, however, between low-capital banks and other banks. For example, increases in equity generally do not lead to increases in assets unless the bank has low capital. We also find that the impact of regulatory variables, such as the ratio of equity to total assets or the of ratio risk-weighted assets to total assets, have the predicted, significant effects for low-capital banks but not necessarily for other banks.     

Joint Effects of Interest Rate Deregulation and Capital Requirements on Optimal Bank Portfolio Adjustments

The 1980 Depository Institution Deregulation and Monetary Control Act (DIDMCA) mandates that Regulation Q be phased out by 1986. With deregulation of interest rate ceilings, the cost of raising capital funds for commercial banks would become more volatile and more closely related with interest rates in the money and capital markets. Thus, value-maximizing bank managers would need to be concerned not only with the internal risk, but also with the external risk in bank portfolio management decisions. Based upon the cash flow version of the capital asset pricing model, this paper analyzes the joint impact of interest rate deregulation and capital requirements on the portfolio behavior of a banking firm.     

Banking competition and welfare

We develop a simple general equilibrium model in which investment in a risky technology is subject to moral hazard and banks can extract market power rents. We show that more bank competition results in lower economy-wide risk, higher social welfare, lower bank capital ratios, more efficient production plans and Pareto-ranked real allocations. Perfect competition supports a second best allocation and optimal levels of bank risk and capitalization. These results are at variance with those obtained by a large literature that has studied a similar environment in partial equilibrium, they are empirically relevant, and carry significant implications for policy guidance.     

Risk in Banking and Capital Regulation

This paper investigates the role of bank capital regulation in risk control. It is known that banks choose portfolios of higher risk because of inefficiently priced deposit insurance. Bank capital regulation is a way to redress this bias toward risk. Utilizing the mean-variance model, the following results are shown: (a) the use of simple capital ratios in regulation is an ineffective means to bound the insolvency risk of banks; (b) as a solution to problems of the capital ratio regulation, the “theoretically correct” risk weights under the risk-based capital plan are explicitly derived; and (c) the “theoretically correct” risk weights are restrictions on asset composition, which alters the optimal portfolio choice of banking firms.     

Bank capital and credit market competition: Will competitive pressure lead to higher capital levels?

This paper establishes a theoretical model to study the relationship between credit market competition and bank capital. In the model, bank capital can alleviate the debt overhang problem, and the extent to which banks can enjoy the gain of holding capital is decreasing in the competitive pressure in the credit market. It is shown that credit market competition reduces banks' incentive to hold capital. Deposit insurance also induces banks to hold less capital. In addition, bank capital regulation is welfare improving, and banks may voluntarily hold capital in excess of regulatory minimums.     

A NEW APPROACH TO CAPITAL BUDGETING FOR FINANCIAL INSTITUTIONS

The classic approach to capital budgeting based on the standard Capital Asset Pricing Model (CAPM) says that the hurdle rate (or cost of capital) for any new project or investment should depend only on the riskiness of that investment. Thus, the hurdle rate, and hence the expected value of the investment, should not be affected by the financial policy of the company evaluating the project. Nor should the hurdle rate be influenced by the company's risk management policy, or by the kind of assets it already has on the balance sheet. This article argues that such a “singlefactor” model may be inappropriate for banks and other financial institutions for two main reasons:

• ? it is especially costly for banks to raise new external funds on short notice;
• ? it is costly for banks to hold a buffer stock of equity capital on the balance sheet, even if this equity is accumulated over time through retained earnings.

The single-factor CAPM ignores such costs and, in so doing, understates the true economic costs of “illiquid” bank investments. Illiquid investments require special treatment because they impose risks that, although “diversifiable” by shareholders, cannot be readily hedged by the bank and therefore require it to hold more equity capital. The authors accordingly propose a “two-factor” model for capital budgeting— one in which banks' investment decisions are linked to their capital structure and risk management decisions. One of the key implications of the two-factor model is that a bank should evaluate new investments according to both their correlation with the market portfolio and their correlation with the bank's existing portfolio of unhedgeable risks. The authors describe several potential applications of their model, including the evaluation of proprietary trading operations and the pricing of unhedgeable derivatives positions. They also compare their approach to the RAROC methodology that has been adopted by a number of banks.     

The Coordination Role of Stress Tests in Bank Risk‐Taking

We examine whether stress tests distort banks' risk‐taking decisions. We study a model in which a regulator may choose to rescue banks in the event of concurrent bank failures. Our analysis reveals a novel coordination role of stress tests. Disclosure of stress‐test results informs banks of the failure likelihood of other banks, which can reduce welfare by facilitating banks' coordination in risk‐taking. However, conducting stress tests also enables the regulator to more effectively intervene banks, coordinating them preemptively into taking lower risks. We find that, if the regulator has a strong incentive to bail out, stress tests improve welfare, whereas if the regulator's incentive to bail out is weak, stress tests impair welfare.     

Bank earnings and regulatory capital management using available for sale securities

Based on a large sample of publicly listed and non-listed US commercial banks from 1996 to 2011, we find robust evidence consistent with banks using realized available for sale (AFS) securities gains and losses to smooth earnings and increase low regulatory capital. We also find that (i) banks with positive earnings smooth earnings, and banks with negative earnings generally take big baths; (ii) regulatory capital constrains big baths; (iii) banks with more negative earnings and more unrealized beginning-of-quarter losses (gains) take big baths (smooth earnings); and (iv) banks with low regulatory capital and more unrealized gains realize more gains. Also, banks with negative earnings take big baths (avoid or reduce the earnings loss) if their unrealized gains are insufficient (sufficient) to offset the negative earnings. Our inferences apply to listed and non-listed banks, which indicates that the earnings management incentives do not derive solely from public capital markets. Our findings reveal that the accounting for AFS securities gains and losses enables banks to manage regulatory capital and earnings in a variety of ways.     

What makes a bank risky? Insights from the optimal capital structure of banks

Assessing the risk of bank failures is the paramount concern of bank regulation. This paper argues that in order to assess the default risk of a bank, it is important to consider its financing decisions as an endogenous dynamic process. We provide a continuous-time model, where banks choose the deposit volume in order to trade off the benefits of earning deposit premiums against the costs that occur at future capital structure adjustments. The bank’s asset value may suffer from shocks and follows a jump-diffusion process.     

Bank portfolio choice with private information about loan quality: Theory and implications for regulation

This paper models bank asset choice when shareholders know more about loan quality than do outsiders. Because of this informational asymmetry, the price of loans in the secondary market is the price for poor quality loans. Banks desire to hold marketable securities in order to avoid liquidating good quality loans at the ‘lemons’ price, but also have a countervailing desire to hold risky loans in order to maximize the value of deposit insurance. In this context, portfolio composition and bank safety is examined as a function of the market distribution of loan quality, and the distribution of deposits. The model suggests that off-balance sheet commitments have little effect on bankruptcy risk, and induce banks to hold more securities. We also show that an increase in the bank equity requirement will unambiguously increase bank safety in the long run. In the short run, banks are unambiguously riskier on-balance sheet, although the effect on bank safety is ambiguous.     

资本缓冲与银行风险变动：周期性及多元化的视角

利用上市银行2002-2013年的季度数据,考察资本缓冲调整、宏观经济波动与资产价值变动之间的内在联系.研究发现:上市银行资本缓冲的顺周期性并不显著,但是其风险变动却对宏观经济的波动极为敏感;同时,资本缓冲的调整与上市银行的风险变动具有相关性,在宏观经济变动时,银行会因自身表内资产组合风险的变化而连续调整其资本缓冲.此外,上市银行表内资产的多元化程度较低,收入变动与风险波动的相关性较显著,所以,收入多元化依然是银行减少风险,提高市场竞争力的驱动因素之一.     

Derivatives Activity at Troubled Banks

Because of moral hazard associated with deposit insurance, troubled banks that have a relatively thin capital cushion to absorb losses have an incentive to take speculative positions. Thus, the prevalence of problem banks among those actively engaged in derivatives markets should be of concern to bank supervisors. However, we find no evidence that bank supervisors take into account, either favorably or unfavorably, the derivatives activities of troubled banks in their decisions to downgrade bank ratings or impose regulatory actions. The derivatives activity of troubled banks should raise the same concerns expressed about banks' on–balance-sheet positions, namely, that they may not be fully exploiting hedging opportunities or may be placing their remaining capital at risk, intentionally or unintentionally.