On measuring concentration in banking systems

Assuming a Pareto-type distribution of bank sizes, we investigate the effect of changes in Zipf's exponent () and the sample size on the behavior of different concentration indices, such as the 3-bank concentration ratio, the Herfindahl–Hirschman index and the top 5%-concentration ratio. We derive analytical relations between these concentration indices and investigate the elasticity of these indices to changes in and in the sample size N. We show different regimes under which each index can be used most appropriately. Our results are highly relevant for policymakers who rely on such concentration measures to derive public policy recommendations in banking.     

On measuring nonlinear risk with scarce observations

We propose a methodology for estimating the risk of portfolios that exhibit nonlinear dependence on the risk driving factors and have scarce observations, which is typical for portfolios of investments in hedge funds. The methodology consists of two steps: first, regressing the portfolio return on nonlinear functions of each single risk driving factor and second, merging together the obtained estimates taking into account the dependence between different factors. Performing the second step leads us to a certain probabilistic problem, for which we propose an analytic and computationally feasible solution for the case where the joint law of the factors is a Gaussian copula. A typical practical application can be to estimate the risk of a hedge fund or a portfolio of hedge funds. As a theoretical consequence of our results, we propose a new definition of the factor risk, i.e., the risk of a portfolio brought by a given factor.     

On optimal non-linear income taxation: numerical results revisited

We use the standard Mirrlees (Review of Economics Studies 38:175–208, 1971) structure, but replace the utility functions used in previous simulations with a quadratic utility of consumption with a bliss point. This greatly reduces the curvature of the utility function over consumption. Our simulations demonstrate that this would then lead to an increasing marginal tax rate structure over a wide range of wage levels.     

Testing the CAPM revisited

This paper re-examines the tests of the Sharpe–Lintner Capital Asset Pricing Model (CAPM). The null that the CAPM intercepts are zero is tested for ten size-based stock portfolios and for twenty five book-to-market sorted portfolios using five-year, ten-year and longer sub-periods during 1965–2004. The paper shows that the evidence for rejecting the CAPM on statistical grounds is weaker than the consensus view suggests, and highlights the pitfalls of testing multiple hypotheses with the conventional heteroskedasticity and autocorrelation robust (HAR) test with asymptotic P-values. The conventional test rejects the null for almost all sub-periods, which is consistent with the evidence in the literature. By contrast, the null is not rejected for most of the sub-periods by the new HAR tests developed by Kiefer et al. (2000), Kiefer and Vogelsang (2005), and Sun et al. (2008).     

Ambiguity and the value of information revisited

We analyze the value that decision makers place on the acquisition of information that partially or completely resolves uncertainty over the correct distribution of outcomes. We distinguish two sources of ambiguity of a given message service: posterior uncertainty over the correct probability distribution and uncertainty over the message which will be received. Given this distinction, we present a model where attitudes towards the two sources of ambiguity are separated and we study how these attitudes affect the value of information. The analysis clarifies and integrates seemingly contradictory results obtained previously in the literature.     

On measuring synchronization of bulls and bears: The case of East Asia

This paper implements estimation and testing procedures for comovements of stock market “cycles” or “phases” in Asia. We extend the Harding and Pagan [Harding, D., Pagan, A.P., 2006. Synchronization of cycles. Journal of Econometrics 132 (1), 59–79] test for strong multivariate nonsynchronization (SMNS) between business cycles to a test that allows for an imperfect degree of multivariate synchronization between stock market cycles. Moreover, we propose a test for endogenously determining structural change in the bivariate and multivariate synchronization indices. Upon applying the technique to five Asian stock markets we find a significant increase in the cross country comovements of Asian bullish and bearish periods in 1997. A power study of the stability test suggests that the detected increase in comovement is more of a sudden nature (i.e. contagion or “Asian Flu”) instead of gradual (i.e. financial integration). It is furthermore argued that stock market cycles and their propensity toward (increased) synchronization contain useful information for both investors, policy makers and financial regulators.     

On measuring serial correlation: Implications for finance and accounting research studies

Accounting and finance studies that measure serial correlation implicitly make two assumptions. One, the studies assume that the sample estimate of the autocorrelation coefficient is unbiased. The assumption is intuitively appealing, but incorrect. This article provides a measure of the size of the bias. Two, the studies assume that the target of the time series is constant over time. However, over a long period target values may change. This article models the general case in which not only do random shocks affect actual values, but also random changes affect target values.     

The optimal rate of inflation revisited

Inflation viewed as a tax on cash balances is investigated using the optimal commodity tax framework. The optimal inflation rate is shown to depend on the effect of changes in the rate of inflation on quantity demanded of ‘costly-to-produce’ goods. Even when other goods are taxed, it is not always optimal to have a positive tax on money, as Phelps and others have claimed. A zero tax or even a rate of deflation greater than the pre-tax rate of interest may be optimal.     

UK student banking revisited: Influences and the decision-making process

This study explores the student decision-making process and in particular the criteria that influence students' choice of retail bank for their account. There has been little recent research in this area and this study updates previous research in line with the changes to the student banking industry. Students are now much more sophisticated in their choice decisions, and location convenience, which proved to be an influential factor in previous studies, is no longer given with such importance.     

Tocqueville revisited. The meaning of American prosperity

Why is business so admired in the United States and so often denigrated in Europe? How has America created 30 million new jobs in the last 20 years while the European Union, with a bigger population, only managed 5 million? What is feeding America's apparently inexhaustible appetite for growth and its recent dramatic improvements in productivity? In 1831, French philosopher Alexis de Tocqueville came to America to examine its prison system and returned with a vision of democracy so profound it has become part of our cultural heritage. More than a century and a half later, renowned British business philosopher Charles Handy retraces Tocqueville's intellectual journey, this time focusing not on democracy but on capitalism. The result is an eye-opening look at some of the fundamental assumptions underpinning business in America today. It is America's optimism that Handy finds most striking, the unquestioned belief that tomorrow can--and should--be made better than today. He contrasts this with the Spaniards when they came to the New World: No haya novedades, those Spaniards would say, "Let nothing new arise." The energy engendered by American optimism, coupled with the Puritan belief in work and in the nobility of earned wealth (as opposed to Europe's furtive attitude toward its nobility's inherited wealth) lies, in Handy's view, at the heart of America's success. Will American capitalism, born as it was from a property-owning democracy, now adapt to a dematerialized world, where property is intellectual rather than physical? Handy draws no absolute conclusions, but rather lays out the challenges that must be overcome for tomorrow to indeed continue to be better than today in this still-young country.     

Regionality revisited: An examination of the direction of spread of currency crises

What determines the direction of spread of currency crises? We examine data on waves of currency crises in 1992, 1994, 1997, and 1998 to evaluate several hypotheses on the determinants of contagion. We simultaneously consider trade competition, financial links, and institutional similarity to the “ground zero” country as potential drivers of contagion. To overcome data limitations and account for model uncertainty, we utilize Bayesian methodologies hitherto unused in the empirical literature on contagion. In particular, we use the Bayesian averaging of binary models that allows us to take into account the uncertainty regarding the appropriate set of regressors.We find that institutional similarity to the ground zero country plays an important role in determining the direction of contagion in all the emerging market currency crises in our dataset. We thus provide persuasive evidence in favour of the “wake-up call” hypothesis for financial contagion. Trade and financial links may also play a role in determining the direction of contagion, but their importance varies amongst the crisis periods.     

Optimal insurance contracts without the non-negativity constraint on indemnities: revisited

In the literature on optimal indemnity schedules, indemnities are usually restricted to be non-negative. Keeler [1974] and Gollier [1987] show that this constraint might well bind: insured could get higher expected utility if insurance contracts would allow payments from the insured to the insurer at some losses. This paper extends Collier’s findings by allowing for negative indemnity payments for a broader class of insurers’ cost functions and argues that the indemnity schedule derived here is more appropriate for practical applications (e.g. in health insurance). JEL Classification D80 · D81 · D89     

Monitoring the “invisible” hand of market discipline: Capital adequacy revisited

The recent U.S. financial crisis and governmental bailout of financial institutions have intensified the debate on the need for effectively measuring and monitoring the financial institutions’ risks. This paper contributes to this discussion by introducing a market-based capital measurement that better captures the dynamics of bank risk and returns. Evidence confirms that these market-based capital adequacy metrics are much more sensitive to risk factors and more responsive to economic events than the traditional accounting/regulatory report based capital models, which often underestimate the true capital needs. The CDS premia, another market-bases solvency measure, seems to overreact to declines in capital adequacy.     

Stock returns and inflation revisited: An evaluation of the inflation illusion hypothesis

Several hypotheses have been proposed to explain the stock return–inflation relation. The Modigliani and Cohn’s inflation illusion hypothesis has received renewed attention. Another hypothesis is the two-regime hypothesis. We reexamine these hypotheses using long sample data of the US and international data. We find that the inflation illusion hypothesis can explain the post-war negative stock return–inflation relation, but it is not compatible with the pre-war positive relation. Using a structural VAR identification method, we show that there are two regimes with positive and negative stock return–inflation relations not only in each period of the US but also in every developed country we consider. This seems inconsistent with the inflation illusion hypothesis that predicts only a negative relation.     

Inter-industry wage differentials revisited: Wage volatility and the option value of mobility

Analysis of data from the PSID reveals that idiosyncratic wage volatility varies inversely with inter-industry wage differentials and is positively correlated with both returns to industry tenure and rates of inter-industry mobility. An incomplete markets life cycle model in which inter-industry mobility decisions and wage differentials are endogenously determined in equilibrium is then developed and shown to be capable of rationalizing these features of the data. In the model, the ability of worker to switch industries generates option value that is large enough to offset the standard risk premium that workers demand for exposure to excess wage volatility.     

Put-call parity revisited: intradaily tests in the foreign currency options market

We test exchange-traded (PHLX) German mark options for conformance to put-call parity (PCP). Puts and calls are matched to the nearest minute, and the relative impact of competing spot exchange rate sources (Reuters vs. Telerate) is assessed. We find that PCP usually holds (roughly 96% of put-call pairs), with the exception of a notable incident in the European options pits. In those instances in which PCP is violated, we find sharp intradaily and intraweekly seasonalities for American options, with disproportionate PCP violations occurring during the relatively light trading periods in early evening and on Fridays. We also conclude that the Telerate prices as recorded by the PHLX are not as accurate as the Reuters exchange rates provided by Olsen and Associates, probably because of time lags in the Telerate data.     

Testing the expectations hypothesis when interest rates are near integrated

Nominal interest rates are unlikely to be generated by unit-root processes. Using data on short and long interest rates from eight developed and six emerging economies, we test the expectations hypothesis using cointegration methods under the assumption that interest rates are near integrated. If the null hypothesis of no cointegration is rejected, we then test whether the estimated cointegrating vector is consistent with that suggested by the expectations hypothesis. The results show support for cointegration in 10 of the 14 countries we consider, and the cointegrating vector is similar across countries. However, the parameters differ from those suggested by theory. We relate our findings to existing literature on the failure of the expectations hypothesis and to the role of term premia.     

银行与股票市场越走越近

西方一位营销专家、曾经这样描述过五六十年代西方商业银行传统业务的繁荣景象：“主管信贷的银行高级职员，面色呆板地把客户安排在大写字台前比自己低得多的觉子上，居高临下，颐指气使。阳光透过窗子照在孤立无援的贷款者身上，他正在对银行的高级职员叙述着自己的贷款理由，而冰；争的银行大楼则宛如希腊神殿．让人不寒而粟。”     

Modeling and measuring intraday overreaction of stock prices

We introduce a model for stock prices consisting of a fundamental price process and a news impact curve, which allows for either overreaction, underreaction, or correct response to changes of the fundamental value. We further develop statistics based on OHLC data, which separately measure upside and downside overreaction. The distribution of these statistics under the hypothesis of correct response and fundamental prices following Brownian motions is used to derive tests for upside and downside overreaction. We show that more realistic and frequently used fundamental price processes with correct response leave the distribution of the test statistics widely unaffected or lead to conservative tests. Empirical application to different stock markets provides strong evidence for intraday overreaction, particularly to bad news. The economic significance of the discrimination induced by the proposed statistics is further illustrated by analyzing the performance of a simple buy on bad news strategy.