The low return distortion of the Sharpe ratio

This article formalizes the undesirable property of the Sharpe ratio that a fund with a certain poor performance can increase its Sharpe ratio in a prospective period by generating a sufficiently negative excess return. Specifically, we set out the conditions that a fund must meet to be exposed to this kind of effect. Furthermore, we provide a formal statement of the excess return value that needs to be deceeded to obtain a higher Sharpe ratio. In an empirical application, we investigate the practical relevance of this kind of distortion. We find that an economically significant number of funds listed in the CISDM hedge fund database have at least once reported a sufficiently negative return, causing an increased Sharpe ratio fund performance.     

Frequency of observation and the estimation of integrated volatility in deep and liquid financial markets

Using two newly available ultrahigh-frequency datasets, we investigate empirically how frequently one can sample certain foreign exchange and U.S. Treasury security returns without contaminating estimates of their integrated volatility with market microstructure noise. Using the standard realized volatility estimator, we find that one can sample dollar/euro returns as frequently as once every 15 to 20 s without contaminating estimates of integrated volatility; 10-year Treasury note returns may be sampled as frequently as once every 2 to 3 min on days without U.S. macroeconomic announcements, and as frequently as once every 40 s on announcement days. Using a simple realized kernel estimator, this sampling frequency can be increased to once every 2 to 5 s for dollar/euro returns and to about once every 30 to 40 s for T-note returns. These sampling frequencies, especially in the case of dollar/euro returns, are much higher than those that are generally recommended in the empirical literature on realized volatility in equity markets. The higher sampling frequencies for dollar/euro and T-note returns likely reflect the superior depth and liquidity of these markets.     

The Effect of Fuel Price Changes on Fleet Demand for New Vehicle Fuel Economy

New vehicle purchases by private companies and government agencies, or ‘fleet’ buyers, represent a significant percentage of overall new vehicle sales in the United States. Yet little is known about fleet demand for new vehicle fuel economy including how it responds to fuel price changes. Using unique disaggregated data on fleet and household registrations of new vehicles from 2009 to 2016, we estimate how fleet demand for new vehicle fuel economy responds to fuel price changes. We find that fleet purchases of low fuel economy vehicles fall relative to high fuel economy vehicles when gasoline prices increase, a finding that is consistent with fleet buyers’ taking into account capitalization of fuel costs in the second‐hand market. Our estimates imply that raising gasoline prices by one dollar would increase fuel economy of new vehicles acquired by fleet buyers by 0.33 miles per gallon. We estimate a similar response for household buyers during the same period. This result justifies basing fuel economy responses to fuel cost changes on household data alone, an assumption widely used in the vehicle demand literature and the fuel economy valuation literature. We also find, however, that the response to fuel price changes varies across the types of fleet buyers: rental companies respond strongly to fuel price changes, whereas commercial and government buyers are insensitive. Our estimates imply that an increase in the federal gasoline tax would modestly increase fuel economy of vehicles bought by households and rental companies but would have little to no impact on fuel economy of vehicles bought by non‐rental companies and governments.     

Default and Recovery Risk Dependencies in a Simple Credit Risk Model

This paper provides evidence for the relationship between credit quality, recovery rate, and correlation. The paper finds that rating grade, rating shift, and macroeconomic factors provide a highly significant explanation for default risk and recovery risk of US bond issues. The empirical data suggest that default and recovery processes are highly correlated. Therefore, a joint approach is required for estimating time‐varying default probabilities and recovery rates that are conditional on default. This paper develops and applies such a model.     

Are managers strategic in reporting non-earnings news? Evidence on timing and news bundling

Using a comprehensive sample of non-earnings 8-K filings from 2005 to 2013, we examine whether firms strategically report mandatory and voluntary news. In particular, we examine whether firms report negative news when investor attention is low and whether they bundle positive and negative news. Our findings support the notion that managers believe in the existence of investor inattention and strategically report negative news after trading hours. These results particularly apply to public firms, where equity market pressures provide stronger incentives to mitigate market reaction to news by exploiting investor inattention. Further analysis of the market reaction to strategic disclosure uncovers no evidence of investor inattention, consistent with market efficiency. We also observe that public firms are more likely to strategically disclose through news bundling and that the likelihood of this increases with the likelihood of strategic disclosure through timing.     

Career concerns and peer effects in institutional tournaments: Evidence from ECB reserve currency portfolios

Using data on European Central Bank's (ECB's) reserve currency portfolios, we find that money managers react to relative rankings (i.e., own vs. peers’ performance) by adjusting portfolio active risk levels measured ex ante by actual deviations from their benchmark. This occurs in the absence of explicit incentives as no monetary reward is promised for winning this “tournament” among portfolio managers. We collect information on managers’ characteristics, including age, education, tenure, salary, and career path, and investigate the role played by implicit incentives. We provide evidence that both individual career concerns and institutional peer pressure contribute to the documented relationship between ranking and risk taking.     

Risk forecasting in (T)GARCH models with uncorrelated dependent innovations

(G)ARCH-type models are frequently used for the dynamic modelling and forecasting of risk attached to speculative asset returns. While the symmetric and conditionally Gaussian GARCH model has been generalized in a manifold of directions, model innovations are mostly presumed to stem from an underlying IID distribution. For a cross section of 18 stock market indices, we notice that (threshold) (T)GARCH-implied model innovations are likely at odds with the commonly held IID assumption. Two complementary strategies are pursued to evaluate the conditional distributions of consecutive TGARCH innovations, a non-parametric approach and a class of standardized copula distributions. Modelling higher order dependence patterns is found to improve standard TGARCH-implied conditional value-at-risk and expected shortfall out-of-sample forecasts that rely on the notion of IID innovations.     

政党与政权的生命

本文提出了一套关于一党制下的政权巩固理论，并试图利用该理论来解释一党制国家政权寿命长短不一的原因。文章作者认为，在政党建设过程中，政治精英们思忖如何建立强有力的政治支柱时，不得不考虑的两个因素就是反对派势力的强弱和寻租的难易程度。如果反对派势力越弱小，且寻租越容易，那么政权建设的成本就越低，但同时这又将不利于建立一个强大的政党联盟或政党组织，并最终导致一党制政权脆弱而不堪一击，一遇危机就陷入分崩离析的境地。相反，如果执政精英起初就面临强大的反对势力并且寻租的可能性很小，那么他们就会给潜在的盟友提供话语权和决策权，从而推动政党建设。事实也证明诸如此类的执政党在危机来临的时候有更强的柔韧性和生命力。为了证实该理论，作者以几内亚比绍和坦桑尼亚，印尼和菲律宾这两对国家为例进行了详细的阐述。