Extending the Basel II approach to estimate capital requirements for equity investments

Under the Basel II banking regulatory capital regime the capital requirements for credit exposures are calculated using the Asymptotic Single Risk Factor (ASRF) approach. The capital requirement is taken to be the contribution of an exposure to the unexpected loss on the bank’s diversified portfolio. Here we extend this approach to calculate capital requirements for equity investments. We show that in the case when asset values have a normal distribution an analytical formula for the unexpected loss contribution may be developed. We show that the capital requirements for equity investments are quite different to those of credit exposures, since equity investments can suffer substantial loss of value even when the underlying company has not defaulted.     

Capital shocks, bank asset allocation, and the revised Basel Accord

In contrast to the 1988 Basel Accord (Basel I), the revised risk-based capital standards (Basel II) propose regulatory capital requirements based on credit ratings. This paper develops a theoretical model to analyze how banks will adjust their low and high credit risk commercial loans under the proposed newer standard. Capital-constrained banks respond to an adverse capital shock by reducing high credit risk loans, while under certain circumstances, low credit risk loans may actually increase. When compared to Basel I, it is shown that high-risk loans are reduced more under Basel II, but whether a bank reduces total lending more under Basel I or under the revised standards depends on a complex interaction of factors.     

Capital requirements under the credit risk-based framework

This work aims to study the hypothesis of lower capitalization of banks under the risk-based rules introduced in Basel II. In this sense, an assessment of the impact of these rules on the capital requirements for non-financial firms’ credit risk is performed. A comparison with Basel I is presented and intervals of variation for the risk drivers such that capital requirements exceed the ones under Basel I are established. Data for a European country supports the hypothesis of a smaller capitalization of banks under the risk-based framework, as far as credit risk in concerned.     

Bank size and risk-taking under Basel II

We analyze the relationship between bank size and risk-taking under the Basel II Capital Accord. Using a model with imperfect competition and moral hazard, we show that the introduction of an internal ratings based (IRB) approach improves upon flat capital requirements if the approach is applied uniformly across banks and if the costs of implementation are not too high. However, the banks’ right to choose between the standardized and the IRB approaches under Basel II gives larger banks a competitive advantage and, due to fiercer competition, pushes smaller banks to take higher risks. This may even lead to higher aggregate risk-taking.     

Limited partner performance and the maturing of the private equity industry

We evaluate the performance of limited partners? (LPs?) private equity investments over time. Using a sample of 14,380 investments by 1,852 LPs in 1,250 buyout and venture capital funds started between 1991 and 2006, we find that the superior performance of endowment investors in the 1991–1998 period, documented by prior literature, is mostly due to their greater access to the top-performing venture capital partnerships. In the subsequent 1999–2006 period, endowments no longer outperform, no longer have greater access to funds that are likely to restrict access, and do not make better investment selections than other types of institutional investors. Nevertheless, all investor types? private equity investments continue to outperform public markets on average. We discuss how these results are consistent with the general maturing of the industry, as private equity has transitioned from a niche, poorly understood area to a ubiquitous part of institutional investors? portfolios.     

Integrated models of capital adequacy – Why banks are undercapitalised

With the majority of large UK and many US banks collapsing or being forced to raise capital over the 2007–9 period, blaming bankers may be satisfying but is patently insufficient; Basel II and Federal oversight frameworks also deserve criticism. We propose that the current methodological void at the heart of Basel II, Pillar 2 is filled with the recommendation that banks develop fully-integrated models for economic capital that relate asset values to fundamental drivers of risk in the economy to capture systematic effects and inter-asset dependencies in a way that crude correlation assumptions do not. We implement a fully-integrated risk analysis based on the balance sheet of a composite European bank using an economic-scenario generation model calibrated to conditions at the end of 2007. Our results suggest that the more modular, correlation-based approaches to economic capital that currently dominate practice could have led to an undercapitalisation of banks, a result that is clearly of interest given subsequent events. The introduction of integrated economic-scenario-based models in future can improve capital adequacy, enhance Pillar 2’s application and rejuvenate the relevance of the Basel regulatory framework.     

Modelling the economic value of credit rating systems

In this paper we develop a model of the economic value of credit rating systems. Increasing international competition and changes in the regulatory framework driven by the Basel Committee on Banking Supervision (Basel II) called forth incentives for banks to improve their credit rating systems. An improvement of the statistical power of a rating system decreases the potential effects of adverse selection, and, combined with meeting several qualitative standards, decreases the amount of regulatory capital requirements. As a consequence, many banks have to make investment decisions where they have to consider the costs and the potential benefits of improving their rating systems. In our model the quality of a rating system depends on several parameters such as the accuracy of forecasting individual default probabilities and the rating class structure. We measure effects of adverse selection in a competitive one-period framework by parameterizing customer elasticity. Capital requirements are obtained by applying the current framework released by the Basel Committee on Banking Supervision. Results of a numerical analysis indicate that improving a rating system with low accuracy to medium accuracy can increase the annual rate of return on a portfolio by 30–40 bp. This effect is even stronger for banks operating in markets with high customer elasticity and high loss rates. Compared to the estimated implementation costs banks could have a strong incentive to invest in their rating systems. The potential of reduced capital requirements on the portfolio return is rather weak compared to the effect of adverse selection.     

An Assessment of Basel II Procyclicality in Mortgage Portfolios

In this paper we develop a probability of default (PD) model for mortgage loans, taking advantage of the Spanish Credit Register, a comprehensive database on loan characteristics and credit quality. From that model, we calculate different types of PDs: point in time, PIT, through the cycle, TTC, average across the cycle and acyclical. Then, we compare capital requirements coming from the different Basel II approaches. We show that minimum regulatory capital under Basel II can be very sensitive to the risk measurement methodology employed. Thus, the procyclicality of regulatory capital requirements under Basel II is an open question, depending on the way internal rating systems are implemented and their output is utilised. We focus on the mortgage portfolio since it is one of the most under researched areas regarding the impact of Basel II and because it is one of the most important of banks’ portfolios.     

Bank regulation and international financial stability: A case against the 2006 Basel framework for controlling tail risk in trading books

In attempting to promote international financial stability, the Basel Committee on Banking Supervision (2006) provided a framework that sought to control the amount of tail risk that large banks around the world would take in their trading books relative to their corresponding minimum capital requirements. However, many of these banks suffered significant trading losses during the recent financial crisis. Our paper examines whether the Basel framework allowed banks to take substantive tail risk in their trading books without a capital requirement penalty. We find that it allowed banks to do so and that its minimum capital requirements can be notably procyclical. Hence, focusing on the way the Basel framework sought to control the amount of tail risk in trading books relative to their corresponding minimum capital requirements, our paper supports the view that it was not properly designed to promote financial stability. We also discuss alternative regulatory frameworks that would potentially be more effective than the Basel framework in preventing banks from taking substantive tail risk in their trading books without a capital requirement penalty.     

Bank Capital: Lessons from the Financial Crisis

Using a multicountry panel of banks, we study whether better capitalized banks experienced higher stock returns during the financial crisis. We differentiate among various types of capital ratios: the Basel risk‐adjusted ratio, the leverage ratio, the Tier 1 and Tier 2 ratios, and the tangible equity ratio. We find several results: (i) before the crisis, differences in capital did not have much impact on stock returns; (ii) during the crisis, a stronger capital position was associated with better stock market performance, most markedly for larger banks; (iii) the relationship between stock returns and capital is stronger when capital is measured by the leverage ratio rather than the risk‐adjusted capital ratio; (iv) higher quality forms of capital, such as Tier 1 capital and tangible common equity, were more relevant.     

The effect of private investments on banks' capital requirements

A simple leverage ratio restriction is not efficient because it does not discriminate between risky and safe banks. We use a structural and comprehensive model of the firm's asset growth to describe the equity buy-out portfolios' stylized facts for two types of banks. We derive a leverage ratio that depends on the level of risky investments, and balances between the spread on such investments, the cost of capital and the overall power of the supervisor to enforce the capital requirements. This method is more transparent and requires fewer parameters than other commonly used methods. We obtain an incentive-compatible constraint on banks to carry the minimal adequate amount of capital. This constraint enhances the supervisors' ability to enforce the rules ex post, and provide banks with a further incentive to reveal their risk type truthfully.     

Financial stability and Basel II

The Basel II Advanced Internal Ratings (AIRB) approach is compared to capital requirements set using an equilibrium structural credit risk model. Analysis shows the AIRB approach undercapitalizes credit risk relative to regulatory targets and allows wide variation in capital requirements for a given exposure owing to ambiguity in the definitions of loss given default and exposure at default. In contrast, the Foundation Internal Ratings Based (FIRB) approach may over-capitalize credit risk relative to supervisory objectives. It is unclear how Basel II will buttress financial sector stability as it specifies the weakest regulatory capital standard for large complex AIRB banks.      

Loan pricing under Basel capital requirements

We analyze the loan pricing implications of the reform of bank capital regulation known as Basel II. We consider a perfectly competitive market for business loans where, as in the model underlying the internal ratings based (IRB) approach of Basel II, a single risk factor explains the correlation in defaults across firms. Our loan pricing equation implies that low risk firms will achieve reductions in their loan rates by borrowing from banks adopting the IRB approach, while high risk firms will avoid increases in their loan rates by borrowing from banks that adopt the less risk-sensitive standardized approach of Basel II. We also show that only a very high social cost of bank failure might justify the proposed IRB capital charges, partly because the net interest income from performing loans is not counted as a buffer against credit losses. A net interest income correction for IRB capital requirements is proposed.     

Does the market discipline banks? New evidence from regulatory capital mix

While bank capital requirements permit a bank to freely substitute between equity and subordinated debt, lenders and investors view debt and equity as imperfect substitutes. It follows that, after controlling for the level of regulatory capital, the mix of debt in capital isolates the role that the market plays in disciplining banks. I document that the mix of debt in capital affects bank behavior, but only when investors can impose real constraints. In particular, the mix of debt reduces the probability of failure and future distress for BHC-affiliated institutions (where the investor has control rights through an equity position) and for stand-alone banks before the Basel Accord (when debt issues included restrictive covenants). However, substituting equity for subordinated debt at the bank holding company level or in stand-alone banks since the Basel Accord (where the investor has few protections) only increases the probability of distress and failure.     

The cyclical behaviour of European bank capital buffers

Using an unbalanced panel of accounting data from 1997 to 2004 and controlling for individual bank costs and risk, we find capital buffers of the banks in the EU15 have a significant negative co-movement with the cycle. For banks in the accession countries there is significant positive co-movement. Capital buffers of commercial and savings banks, and of large banks, exhibit negative co-movement. Those of co-operative and smaller banks exhibit positive co-movement. Speeds of adjustment are fairly slow. We interpret these results and discuss policy implications, noting that negative co-movement of capital buffers will exacerbate the pro-cyclical impact of Basel II.     

Do different forms of government ownership matter for bank capital behavior? Evidence from China

This study attempts to reconcile the conflicting theoretical predictions regarding how government ownership affects bank capital behaviour. Using a unique Chinese bank dataset over 2006–2015 we find that government-owned banks have higher target capital ratios and adjust these ratios faster compared to private banks, supporting the ‘development/political’ view of the government’s role in banking. This effect is stronger for local government-owned and state enterprise-owned banks than for central government-owned banks. We also find that undercapitalized government-owned banks increase equity while undercapitalized foreign banks contract assets and liabilities as their respective main strategy to adjust their capital ratios.     

The impact of banking regulations on banks' cost and profit efficiency: Cross-country evidence

This paper uses stochastic frontier analysis to provide international evidence on the impact of the regulatory and supervision framework on bank efficiency. Our dataset consists of 2853 observations from 615 publicly quoted commercial banks operating in 74 countries during the period 2000-2004. We investigate the impact of regulations related to the three pillars of Basel II (i.e. capital adequacy requirements, official supervisory power, and market discipline mechanisms), as well as restrictions on bank activities, on cost and profit efficiency of banks, while controlling for other country-specific characteristics. Our results suggest that banking regulations that enhance market discipline and empower the supervisory power of the authorities increase both cost and profit efficiency of banks. In contrast, stricter capital requirements improve cost efficiency but reduce profit efficiency, while restrictions on bank activities have the opposite effect, reducing cost efficiency but improving profit efficiency.     

Cross-country effects of regulatory capital arbitrage

One reason for the recent asset price bubbles in many developed countries could be regulatory capital arbitrage. Regulatory and legal changes can help traditional banks to move their assets off their balance sheets into the lightly regulated shadows and thus enable regulatory arbitrage through the securitized sector. This paper adopts a global vector autoregression (GVAR) methodology to assess the effects of regulatory capital arbitrage on equity prices, house prices and economic activity across 11 OECD countries/regions. A counterfactual experiment disentangles the effects of regulatory arbitrage following a change in the net capital rule for investment banks in April 2004 and the adoption of the Basel II Accord in June 2004. The results provide evidence for the existence of an international finance multiplier, with about half of the countries overshooting U.S. impulse responses. The counterfactual shows that regulatory arbitrage via the U.S. securitized sector may enhance the cross-country reallocation of capital from housing markets towards equity markets.     

Stress testing credit risk: The Great Depression scenario

By employing Moody’s corporate default and rating transition data spanning the last 90 years we explore how much capital banks should hold against their corporate loan portfolios to withstand historical stress scenarios. Specifically, we will focus on the worst case scenario over the observation period, the Great Depression. We find that migration risk and the length of the investment horizon are critical factors when determining bank capital needs in a crisis. We show that capital may need to rise more than three times when the horizon is increased from 1 year, as required by current and future regulation, to 3 years. Increases are still important but of a lower magnitude when migration risk is introduced in the analysis. Further, we find that the new bank capital requirements under the so-called Basel 3 agreement would enable banks to absorb Great Depression-style losses. But, such losses would dent regulatory capital considerably and far beyond the capital buffers that have been proposed to ensure that banks survive crisis periods without government support.     

A Critique of Revised Basel II

This paper critiques the revised Basel II capital requirements for banks. To provide a framework for analysis, the XYZ theory of regulatory capital is formulated. Independent of the XYZ theory, we argue that the revised Basel II capital rule for credit risk is not a good approximation to the ideal rule. Based on this, and using the XYZ theory, we argue that: (1) the revised Basel II rules should not replace the existing approaches for determining minimal capital standards, but should be used in conjunction with them, and (2) that calibrating the capital rules to maintain aggregate market capital is a prudent procedure.