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.     

The level and quality of Value-at-Risk disclosure by commercial banks

In this paper we study both the level of Value-at-Risk (VaR) disclosure and the accuracy of the disclosed VaR figures for a sample of US and international commercial banks. To measure the level of VaR disclosures, we develop a VaR Disclosure Index that captures many different facets of market risk disclosure. Using panel data over the period 1996–2005, we find an overall upward trend in the quantity of information released to the public. We also find that Historical Simulation is by far the most popular VaR method. We assess the accuracy of VaR figures by studying the number of VaR exceedances and whether actual daily VaRs contain information about the volatility of subsequent trading revenues. Unlike the level of VaR disclosure, the quality of VaR disclosure shows no sign of improvement over time. We find that VaR computed using Historical Simulation contains very little information about future volatility.     

Market concentration and the likelihood of financial crises

According to theory, market concentration affects the likelihood of a financial crisis in different ways. The “concentration-stability” and the “concentration-fragility” hypotheses suggest opposing effects operating through specific channels. Using data of 160 countries for the period 1970–2009, this paper empirically tests these indirect effects of financial market structure. We set up a simultaneous system in order to jointly estimate financial stability and the relevant channel variables as endogenous variables. Our findings provide support for the assumption of channel effects in general and both the concentration-stability and the concentration-fragility hypothesis in particular. The effects are found to vary between high and low income countries.     

Systemic risk measures: The simpler the better?

This paper estimates and compares two groups of high-frequency market-based systemic risk measures using European and US interbank rates, stock prices and credit derivatives data from 2004 to 2009. Measures belonging to the macro group gauge the overall tension in the financial sector and micro group measures rely on individual institution information to extract joint distress. We rank the measures using three criteria: (i) Granger causality tests, (ii) Gonzalo and Granger metric, and (iii) correlation with an index of systemic events and policy actions. We find that the best systemic measure in the macro group is the first principal component of a portfolio of Credit Default Swap (CDS) spreads whereas the best measure in the micro group is the multivariate densities computed from CDS spreads. These results suggest that the measures based on CDSs outperform measures based on interbank rates or stock market prices.     

Bank activity and funding strategies: The impact on risk and returns

This paper examines the implications of bank activity and short-term funding strategies for bank risk and return using an international sample of 1,334 banks in 101 countries leading up to the 2008 financial crisis. Expansion into noninterest income-generating activities such as trading increases the rate of return on assets, and it could offer some risk diversification benefits at very low levels. Nondeposit, wholesale funding in contrast lowers the rate of return on assets, while it can offer some risk reduction at commonly observed low levels of nondeposit funding. A sizable proportion of banks, however, attract most of their short-term funding in the form of nondeposits at a cost of enhanced bank fragility. Overall, banking strategies that rely prominently on generating noninterest income or attracting nondeposit funding are very risky, consistent with the demise of the US investment banking sector.     

Dynamic debt runs and financial fragility: Evidence from the 2007 ABCP crisis

We use the 2007 asset-backed commercial paper (ABCP) crisis as a laboratory to study the determinants of debt runs. Our model features dilution risk: maturing short-term lenders demand higher yields in compensation for being diluted by future lenders, making runs more likely. The model explains the observed tenfold increase in yield spreads leading to runs and the positive relation between yield spreads and future runs. Results from structural estimation show that runs are very sensitive to leverage, asset values, and asset liquidity, but less sensitive to the degree of maturity mismatch, the strength of guarantees, and asset volatility.     

Creditor rights,information sharing,and bank risk taking

Looking at a sample of nearly 2,400 banks in 69 countries, we find that stronger creditor rights tend to promote greater bank risk taking. Consistent with this finding, we also show that stronger creditor rights increase the likelihood of financial crisis. On the plus side, we find that stronger creditor rights are associated with higher growth. In contrast, we find that the benefits of information sharing among creditors appear to be universally positive. Greater information sharing leads to higher bank profitability, lower bank risk, a reduced likelihood of financial crisis, and higher economic growth.     

Bank CEO incentives and the credit crisis

We investigate whether bank performance during the recent credit crisis is related to chief executive officer (CEO) incentives before the crisis. We find some evidence that banks with CEOs whose incentives were better aligned with the interests of shareholders performed worse and no evidence that they performed better. Banks with higher option compensation and a larger fraction of compensation in cash bonuses for their CEOs did not perform worse during the crisis. Bank CEOs did not reduce their holdings of shares in anticipation of the crisis or during the crisis. Consequently, they suffered extremely large wealth losses in the wake of the crisis.     

SAFE: An early warning system for systemic banking risk

This paper builds on existing microprudential and macroprudential early warning systems (EWSs) to develop a new, hybrid class of models for systemic risk that incorporates the structural characteristics of the financial system and a feedback amplification mechanism. The models explain financial stress using both public and proprietary supervisory data from systemically important institutions, regressing institutional imbalances using an optimal lag method. The Systemic Assessment of Financial Environment (SAFE) EWS monitors microprudential information from the largest bank holding companies to anticipate the buildup of macroeconomic stresses in the financial markets. To mitigate inherent uncertainty, SAFE develops a set of medium-term forecasting specifications that gives policymakers enough time to take ex-ante policy action and a set of short-term forecasting specifications for verification and adjustment of supervisory actions. This paper highlights the application of these models to stress testing and policy.     

Banking system control,capital allocation,and economy performance

We observe less efficient capital allocation in countries whose banking systems are more thoroughly controlled by tycoons or families. The magnitude of this effect is similar to that of state control over banking. Unlike state control, tycoon or family control also correlates with slower economic and productivity growth, greater financial instability, and worse income inequality. These findings are consistent with theories that elite-capture of a country’s financial system can embed “crony capitalism.”     

Nonlinear portfolio selection using approximate parametric Value-at-Risk

As the skewed return distribution is a prominent feature in nonlinear portfolio selection problems which involve derivative assets with nonlinear payoff structures, Value-at-Risk (VaR) is particularly suitable to serve as a risk measure in nonlinear portfolio selection. Unfortunately, the nonlinear portfolio selection formulation using VaR risk measure is in general a computationally intractable optimization problem. We investigate in this paper nonlinear portfolio selection models using approximate parametric Value-at-Risk. More specifically, we use first-order and second-order approximations of VaR for constructing portfolio selection models, and show that the portfolio selection models based on Delta-only, Delta–Gamma-normal and worst-case Delta–Gamma VaR approximations can be reformulated as second-order cone programs, which are polynomially solvable using interior-point methods. Our simulation and empirical results suggest that the model using Delta–Gamma-normal VaR approximation performs the best in terms of a balance between approximation accuracy and computational efficiency.     

Does market structure matter on banks’ profitability and stability? Emerging vs. advanced economies

We empirically investigate the effects of market structure on profitability and stability for 1929 banks in 40 emerging and advanced economies over 1999–2008 by incorporating the traditional structure-conduct-performance (SCP) and relative-market-power (RMP) hypotheses. We observe that a greater market share leads to higher bank profitability being biased toward the RMP hypothesis in advanced economies, yet neither of the hypotheses is supported for profitability in emerging economies. The SCP appears to exert a destabilising effect on advanced banks, suggesting that a more concentrated banking system may be vulnerable to financial instability, however, the RMP seems to perform a stabilising effect in both economies. Evidence also highlights that profitability and stability increase with an increased interest-margin revenues in a less competitive environment for emerging markets. Overall, these results suggest that although policy measures to promote competition may dampen economic rent, excessive implementation may have an undesired destabilising impact on banks.     

Paulson's gift

We calculate the costs and benefits of the largest ever US government intervention in the financial sector announced during the 2008 Columbus-day weekend. We estimate that this intervention increased the value of banks’ financial claims by $130 billion (bn) at a taxpayers’ cost of $21–$44 billion with a net benefit between $86 and $109 bn. By looking at the limited cross section, we infer that this net benefit arises from a reduction in the probability of bankruptcy, which we estimate would destroy 22% of the enterprise value. The big winners of the plan were the bondholders of the three former investment banks and Citigroup, while the losers were JP Morgan shareholders and the US taxpayers.     

How does capital affect bank performance during financial crises?

This paper empirically examines how capital affects a bank’s performance (survival and market share) and how this effect varies across banking crises, market crises, and normal times that occurred in the US over the past quarter century. We have two main results. First, capital helps small banks to increase their probability of survival and market share at all times (during banking crises, market crises, and normal times). Second, capital enhances the performance of medium and large banks primarily during banking crises. Additional tests explore channels through which capital generates these effects. Numerous robustness checks and additional tests are performed.     

The credit crisis around the globe: Why did some banks perform better?

Though overall bank performance from July 2007 to December 2008 was the worst since the Great Depression, there is significant variation in the cross-section of stock returns of large banks across the world during that period. We use this variation to evaluate the importance of factors that have been put forth as having contributed to the poor performance of banks during the credit crisis. The evidence is supportive of theories that emphasize the fragility of banks financed with short-term capital market funding. The better-performing banks had less leverage and lower returns immediately before the crisis. Differences in banking regulations across countries are generally uncorrelated with the performance of banks during the crisis, except that large banks from countries with more restrictions on bank activities performed better and decreased loans less. Our evidence poses a substantial challenge to those who argue that poor bank governance was a major cause of the crisis because we find that banks with more shareholder-friendly boards performed significantly worse during the crisis than other banks, were not less risky before the crisis, and reduced loans more during the crisis.     

Private equity and regulatory capital

Regulatory capital requirements for European banks have been put forward in the Basel II Capital Framework and subsequently in the capital requirements directive (CRD) of the EU. We provide a detailed discussion of the capital requirements for private equity investments under different approaches. For the internal model approach we present a structural model that we calibrate to a proprietary dataset. We modify the standard Merton structural model to make it applicable in practice and to capture stylized facts of private equity investments. We also implement the early default feature with a fast simulation algorithm. Our results support capital requirements lower than in Basel II, but not as low as in CRD, thereby giving adverse incentives to banks for using advanced risk models. A sensitivity analysis shows that this finding is robust to parameter uncertainty and stress scenarios.     

Dynamic factor Value-at-Risk for large heteroskedastic portfolios

We propose a methodology that can efficiently measure the Value-at-Risk (VaR) of large portfolios with time-varying volatility and correlations by bringing together the established historical simulation framework and recent contributions to the dynamic factor models literature. We find that the proposed methodology performs well relative to widely used VaR methodologies, and is a significant improvement from a computational point of view.     

Bank liquidity,the maturity ladder,and regulation

We investigate the liquidity management of 62 Dutch banks between January 2004 and March 2010, when these banks were subject to a liquidity regulation that is very similar to Basel III’s Liquidity Coverage Ratio (LCR). We find that most banks hold more liquid assets against their stock of liquid liabilities, such as demand deposits, than strictly required under the regulation. More solvent banks hold fewer liquid assets against their stock of liquid liabilities, suggesting an interaction between capital and liquidity buffers. However, this interaction turns out to be weaker during a crisis. Although not required, some banks consider cash flows scheduled beyond 1 month ahead when setting liquidity asset holdings, but they seldom look further ahead than 1 year.     

Deposit insurance coverage,ownership, and banks' risk-taking in emerging markets

We ask how deposit insurance systems and ownership of banks affect the degree of market discipline on banks' risk-taking. Market discipline is determined by the extent of explicit deposit insurance, as well as by the credibility of non-insurance of groups of depositors and other creditors. Furthermore, market discipline depends on the ownership structure of banks and the responsiveness of bank managers to market incentives. An expected U-shaped relationship between explicit deposit insurance coverage and banks' risk-taking is influenced by country specific institutional factors, including bank ownership. We analyze specifically how government ownership, foreign ownership and shareholder rights affect the disciplinary effect of partial deposit insurance systems in a cross-section analysis of industrial and emerging market economies, as well as in emerging markets alone. The coverage that maximizes market discipline depends on country-specific characteristics of bank governance. This “risk-minimizing” deposit insurance coverage is compared to the actual coverage in a group of countries in emerging markets in Eastern Europe and Asia.     

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.