The pernicious effects of contaminated data in risk management

Banks hold capital to guard against unexpected surges in losses and long freezes in financial markets. The minimum level of capital is set by banking regulators as a function of the banks’ own estimates of their risk exposures. As a result, a great challenge for both banks and regulators is to validate internal risk models. We show that a large fraction of US and international banks uses contaminated data when testing their models. In particular, most banks validate their market risk model using profit-and-loss (P/L) data that include fees and commissions and intraday trading revenues. This practice is inconsistent with the definition of the employed market risk measure. Using both bank data and simulations, we find that data contamination has dramatic implications for model validation and can lead to the acceptance of misspecified risk models. Moreover, our estimates suggest that the use of contaminated data can significantly reduce (market-risk induced) regulatory capital.     

Ownership structure, market discipline, and banks’ risk-taking incentives under deposit insurance

The paper studies the effects of market discipline by creditors and ownership structure on banks’ risk taking in the presence of partial deposit insurance. An agency-cost model explains how the effects of creditor discipline and shareholder control are interdependent, the non-monotonic effect of shareholder control, and the role of leverage. Panel regressions on several hundred banks worldwide 1995-2005 confirm a negative individual risk effect of creditor discipline and the expected convex effect of shareholder control. Increased shareholder control significantly strengthens the negative effect of market discipline on asset risk, but joint effects on overall default risk are limited.     

Impact of FDICIA internal controls on bank risk taking

The Federal Deposit Insurance Corporation Improvement Act (FDICIA) of 1991 was designed, among other things, to introduce risk-based deposit insurance, increase capital requirements, and improve banks’ internal controls. Of particular interest in this study are the requirements for annual audit and reporting of management’s and auditor’s assessment of the effectiveness of internal control for banks with $500 million or more in total assets (raised to $1 billion in 2005). We study the impact of these requirements on banks’ risk-taking behavior prior to the recent financial crisis and the consequent implications for bank failure and financial trouble during the crisis period. Using a sample of 1138 banks, we provide evidence that banks required to comply with the FDICIA internal control requirements have lower risk taking in the pre-crisis period. Specifically, the volatility of net interest margin, the volatility of earnings, and Z score show less risk-taking behavior. Furthermore, these banks are less likely to experience failure and financial trouble during the crisis period.     

Banks’ capital buffer,risk and performance in the Canadian banking system: Impact of business cycles and regulatory changes

Using quarterly financial statements and stock market data from 1982 to 2010 for the six largest Canadian chartered banks, this paper documents positive co-movement between Canadian banks’ capital buffer and business cycles. The adoption of Basel Accords and the balance sheet leverage cap imposed by Canadian banking regulations did not change this cyclical behavior of Canadian bank capital. We find Canadian banks to be well-capitalized and that they hold a larger capital buffer in expansion than in recession, which may explain how they weathered the recent subprime financial crisis so well. This evidence that Canadian banks ride the business and regulatory periods underscores the appropriateness of a both micro- and a macro-prudential “through-the-cycle” approach to capital adequacy as advocated in the proposed Basel III framework to strengthen the resilience of the banking sector.     

Differential impact of Korean banking system reforms on bank productivity

We study the impact of banking system reforms during a crisis following a period of undisciplined lending. Regulatory changes aimed at strengthening the banks’ capital structure and risk management practices do not have a uniform impact on bank productivity, but rather favor financially sound or strategically privileged banks. We present evidence documenting the differential impact of regulatory reforms on Korean commercial bank productivity over the period 1995–2005. Average technical efficiency of banks decreased during the financial crisis of 1997–1998. It improved following the subsequent bank restructuring and continued to improve through 2005. The capital adequacy ratio is positively associated with banks’ technical efficiency. The non-performing loans ratio is negatively associated with technical efficiency. Both relationships are accentuated during the crisis but attenuated after the reforms.     

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.     

Consolidation in banking and financial stability in Europe: Empirical evidence

Using aggregate balance sheet data from banks across the EU-25 over the period from 1997 to 2005 we provide empirical evidence that national banking market concentration has a negative impact on European banks’ financial soundness as measured by the Z-score technique while controlling for macroeconomic, bank-specific, regulatory, and institutional factors. Furthermore, our analysis reveals that Eastern European banking markets exhibiting a lower level of competitive pressure, fewer diversification opportunities and a higher fraction of government-owned banks are more prone to financial fragility whereas capital regulations have supported financial stability across the entire European Union.     

The impact of bank ownership concentration on impaired loans and capital adequacy

This paper examines the impact of bank ownership concentration on two indicators of bank riskiness, namely banks’ non-performing loans and capital adequacy. Using balance sheet information for around 500 commercial banks from more than 50 countries averaged over 2005–2007, we find that concentrated ownership (proxied by different levels of shareholding) significantly reduces a bank’s non-performing loans ratio, conditional on supervisory control and shareholders protection rights. Furthermore, ownership concentration affects the capital adequacy ratio positively conditional on shareholder protection. At low levels of shareholder protection rights and supervisory control, ownership concentration reduces bank riskiness.     

The expansion of services in European banking: Implications for loan pricing and interest margins

Our study of 602 European banks over 1996–2002 investigates how the banks’ expansion into fee-based services has affected their interest margins and loan pricing. We find that higher income share from commissions and fees is associated with lower margins and loan spreads. The higher the commission and fee income share, moreover, the weaker the link between bank loan spreads and loan risk. The latter result is consistent with the conjecture that banks price (or misprice) loans to increase sales of other services. That loss leader (or cross selling) hypothesis has implications for bank regulation and competition with (non-bank) lenders.     

Diversification and Value-at-Risk

A pervasive and puzzling feature of banks’ Value-at-Risk (VaR) is its abnormally high level, which leads to excessive regulatory capital. A possible explanation for the tendency of commercial banks to overstate their VaR is that they incompletely account for the diversification effect among broad risk categories (e.g., equity, interest rate, commodity, credit spread, and foreign exchange). By underestimating the diversification effect, bank’s proprietary VaR models produce overly prudent market risk assessments. In this paper, we examine empirically the validity of this hypothesis using actual VaR data from major US commercial banks. In contrast to the VaR diversification hypothesis, we find that US banks show no sign of systematic underestimation of the diversification effect. In particular, diversification effects used by banks is very close to (and quite often larger than) our empirical diversification estimates. A direct implication of this finding is that individual VaRs for each broad risk category, just like aggregate VaRs, are biased risk assessments.     

Basel II and bank lending to emerging markets: Evidence from the German banking sector

This paper investigates whether the new Basel Accord will induce a change in bank lending to emerging markets using a comprehensive new data set on German banks’ foreign exposure. We test two interlinked hypotheses on the conditions under which the change in the regulatory capital would leave lending flows unaffected. This would be the case if (i) the new regulatory capital requirement remains below the economic capital and (ii) banks’ economic capital to emerging markets already adequately reflects risk. On both accounts the evidence indicates that the new Basel Accord should have a limited effect on lending to emerging markets.     

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.     

Transatlantic systemic risk

In this paper we study systemic risk for the US and Europe. We show that banks’ exposures to common risk factors are crucial for systemic risk. We come to this conclusion by first showing that relations between US and European banks are smaller than within each region. We then show that European banks react more strongly to the onset of the financial crisis than US banks. Regarding the consequences of systemic risk, we show that dependence between the banking sector and a wide range of real sectors is limited. Our results imply that regulators and supervisors should address international bank dependencies arising from common risk factors, while recessions in real sectors due to bank defaults should be a secondary concern.     

Bank resilience to systemic shocks and the stability of banking systems: Small is beautiful

Utilising a novel empirical approach and an extensive sample of listed European banks, we identify which bank characteristics offer a shelter from systemic shocks and compare the relative effects of several hypothetical prudential rules on a bank’s risk exposure. While the results show that restrictions on a bank’s leverage ratio and the imposition of liquidity requirements, as in the Basel III Accord, may improve the resilience of a bank to systemic events, they also demonstrate that bank size, the share of non-interest income and asset growth (none of which are at the centre of the new regulatory landscape) are key determinants of a bank’s risk exposure. In particular, the introduction of a cap on bank absolute size appears the most effective tool, ceteris paribus, to reduce the default risk of a bank given systemic events. Furthermore, in spite of the integration process of the financial industry in Europe, the analysis presented here shows that such a cap should be country-specific with smaller economies requiring smaller banks. Finally, we show that the strengthening of individual bank stability obtained via size restrictions is accompanied by a reduction of the contribution to systemic risk for banks which are relatively large compared to the domestic economy.     

Systemic risk contributions: A credit portfolio approach

We put forward a framework for measuring systemic risk and attributing it to individual banks. Systemic risk is coherently measured as the expected loss to depositors and investors when a systemic event occurs. The risk contributions are calculated so as to ensure a full risk allocation among institutions. Applying our methodology to a panel of 54–86 of the world’s major commercial banks for a 13-year time span with monthly frequency not only allows us to closely match the list of G-SIBs; we can also use individual risk contributions to compute bank-specific surcharges: systemic capital charges as well as countercyclical buffers. We therefore address both dimensions of systemic risk – cross-sectional and time-series – in a single integrated approach. As the analysis of risk drivers confirms, the main focus of macroprudential supervision should be on a solid capital base throughout the financial cycle and de-correlation of banks’ asset values.     

The term structure of CD rates and monetary policy transmission

The paper investigates the term structure of CD rates and its relationship with the federal funds rate or monetary policy. The term structure derived in this paper is governed primarily by the federal funds rate and secondarily by banks’ income smoothing behavior. It is consistent with the estimation results and differs significantly from the standard term structure of interest rates. The downturn phase of business cycles appears to be accompanied by more aggressive income smoothing by banks (compared with the upturn phase) due to their pessimistic expectations of future profits. The compositional shift in banks’ liabilities during the downturn phase away from CDs toward transaction deposits may pose a greater withdrawal risk for banks.     

A perspective on the symptoms and causes of the financial crisis

Prior to the 2007–2008 financial crisis, banking sector profits were very high but the profitability of financial intermediation was poor. Using a novel model of banking, this article argues that the high profits were achieved through balance sheet expansion and growing default, liquidity, and term risk mismatches between assets and liabilities. As a result, large banks’ financial leverage rose as they became less liquid, setting the conditions for a systemic banking crisis. This article argues that the increase in financial leverage was possible due to misguided changes in the regulatory framework, specifically, the Basel I capital accord and reductions in reserve requirements. Finally, this article overviews and assesses the policy response in the aftermath of the crisis.     

Incorporating risk input into the analysis of bank productivity: Application to the Taiwanese banking industry

This study reappraises banks’ productivity by using 42 Taiwanese banks during 1999–2007 as observations. It introduces an input-oriented generalized metafrontier Malmquist productivity index (I-gMMPI), while considering the latent effect of risk-taking behavior in the analytic framework. We learn that public and private banks should face separate short-term technological frontiers, while the econometric model considering risk input can portray banks’ operating frontiers better. Moreover, neglecting the influence of risk input would bring about distortions of efficiency, technology and TFP dynamic estimations for banks; meanwhile, the degree of scale economies would also be overestimated. The paper concludes that neglecting the risk-taking essence in bank performance evaluation is equal to allowing banks to barter risk-bearing as the term for further output growth. Consequently, the potential cost is that banks may excessively aggrandize their scales of business, implying the possibility of another financial crisis.     

The regulator’s trade-off: Bank supervision vs. minimum capital

We develop a simple model of banking regulation with two policy instruments: minimum capital requirements and the supervision of domestic banks. The regulator faces a trade-off: high capital requirements cause a drop in the banks’ profitability, whereas strict supervision reduces the scope of intermediation and is costly for taxpayers. We show that a mix of both instruments minimises the costs of preventing the collapse of financial intermediation. Once we allow for cross-border banking, the optimal policy is not feasible. If domestic supervisory effort is not observable, our model predicts a race to the bottom in capital requirement regulation. Therefore, countries are better off by harmonising regulation on an international standard.