Implied Sharpe ratios of portfolios with options: Application to Nikkei futures and listed options

We propose a criterion for portfolio selection, implied excess Sharpe ratio. The implied excess Sharpe ratio is intended as an excess Sharpe ratio (versus the underlying stock) that investors can expect to enjoy from portfolios that include options and is a useful ex ante indicator that can be easily calculated. There are a variety of ways to include options in a portfolio, but we theoretically show that the combination that produces the largest implied excess Sharpe ratio is the best way to maximize the short-term Sharpe ratio. The selection process uses implied excess Sharpe ratio, which is easily calculated from stock lending fees implied by stock prices and actual stock lending fee. It does not require historical simulation or prediction of share price average growth rates and is highly transparent as it can be easily reproduced (at a low calculation cost). Hence, the implied excess Sharpe ratio is a simple but effective tool for investors seeking returns in exchange for a certain amount of risk that want to use the options market efficiently. The short-term Sharpe ratio is not necessarily the only criterion, but is a rational benchmark of portfolio performance closely related to criteria such as the long-term Sharpe ratio and maximum drawdown. To examine the benefit of the concept, we construct an investment strategy that automatically selects from multiple candidate portfolios that are made up of combinations of Nikkei futures and Nikkei listed options the portfolio with the largest implied excess Sharpe ratio. Back-testing shows that this investment strategy performs well over the long term as well.     

Robust performance measures for high yield bond funds

We examine performance measures for high yield bond mutual funds, which are a considerable percentage of taxable bond investments, but have not been widely studied. High yield funds exhibit persistence in their monthly returns, so we calculate Sharpe ratios using methods that incorporate the serial correlation of returns. We find that high yield fund rankings using raw returns and conventionally calculated Sharpe ratios are different from those using trailing standard deviations and robust standard errors. High yield fund rankings based on robust Sharpe ratios also differ from those computed using multi-index Jensen's alphas and information ratios. When measured by risk-adjusted returns, high yield bond fund managers do not add much value.     

Distributional properties of portfolio weights

In this paper, we prove several distributional properties for optimal portfolio weights. The weights are estimated by replacing the parameters with the sample counterparts. All results for finite samples are made assuming normally distributed returns. We calculate the exact covariances for the weights obtained by the expected quadratic utility. Additionally we derive the multivariate density function of the global minimum variance portfolio and the univariate density of the tangency portfolio. We obtain the conditional density for the Sharpe ratio optimal weights and show that the expectations of the Sharpe ratio optimal weights do not exist. Moreover, we determine the asymptotic distributions of the estimated weights assuming that the returns follow a multivariate stationary Gaussian process.     

Why SMEs invest in environmental measures: sustainability evidence from small and medium‐sized printing firms

Why do SMEs invest in environmental measures? From the literature we know that most SMEs are rather slow in adopting these sustainable measures, but then the following question arises: why are other SMEs fast in this respect? From our research, it becomes clear that improving the working conditions is the most important reason why these fast‐going SMEs invest in environmental measures, as this probably improves their employees' motivation and performance. This explanation connects ‘planet’ and ‘people’ with each other, and does not exclude ‘profit’, which completes the traditional sustainability circle. Copyright © 2006 John Wiley & Sons, Ltd and ERP Environment.     

A note on the evaluation of long-run investment decisions using the sharpe ratio

This paper reexamines the use of the Sharpe ratio to measure the performance of large and small company stocks along with corporate bonds over different holding periods. It builds on previous research which cites the effects of serial correlation and non-normality in the creation of estimation error in the calculation of the Sharpe ratio. It finds that higher order moments such as skewness and kurtosis are a further source of error that must be accounted for when making inferences about asset performance.     

Does Private Money Buy Public Policy? Campaign Contributions and Regulatory Outcomes in Telecommunications

To what extent can market participants affect the outcomes of regulatory policy? In this paper, we study the effects of one potential source of influence—campaign contributions—from competing interests in the local telecommunications industry, on regulatory policy decisions of state public utility commissions. Our work is unique in that we test the effects of campaign contributions on measurable policy outcomes. This stands in stark relief against most of the existing literature, which examines potentially noisier measures of policy outcomes—such as the roll‐call votes of legislators, to examine how private money may influence public policy. By moving to more direct measures of policy effects, and using a unique new dataset, we find, in contrast to much of the literature on campaign contributions, that there is a significant effect of private money on regulatory outcomes. This result is robust to numerous alternative model specifications. We also assess the extent of omitted variable bias that would have to exist to obviate the estimated result. We find that for our result to be spurious, omitted variables would have to explain more than five times the variation in the mix of private money as is explained by the variables included in our analysis. We consider this to be very unlikely.     

CONSTRUING THE BUSINESS PORTFOLIO: A COGNITIVE MODEL OF DIVERSIFICATION[1]

In investigating the concept of diversification and its link to performance, strategy researchers have tended to emphasize economic, technological, or market characteristics that distinguish or relate one business to another. However, by ignoring the mental maps corporate-level managers use to understand and manage strategic variety among their firm's businesses, strategy research has failed to produce an overall theory that links diversification to performance. Although the literature has begun to reaffirm the importance of developing a cognitive concept of diversification, researchers have been frustrated by the paucity of methods that are suitable for operationalizing the subjective characteristics of managerial mental maps into quantitative and reproducible measures. In addressing this deficit, this article proposes the use of the Repertory Grid, a set of procedures that facilitates elicitation and quantification of top managers' mindsets towards the firm's mix of businesses. After outlining the theoretical and methodological foundations of the Repertory Grid, the paper defines indices of grid structure and content and demonstrates the utility of grid data for assessing diversification.     

ARE WOMEN REALLY MORE RISK‐AVERSE THAN MEN? A RE‐ANALYSIS OF THE LITERATURE USING EXPANDED METHODS

While a substantial literature in economics and finance has concluded that ‘women are more risk averse than men’, this conclusion merits investigation. After briefly clarifying the difference between making generalizations about groups, on the one hand, and making valid inferences from samples, on the other, this essay suggests improvements to how economists communicate our research results. Supplementing findings of statistical significance with quantitative measures of both substantive difference (Cohen's d, a measure in common use in non‐Economics literatures) and of substantive overlap (the Index of Similarity, newly proposed here) adds important nuance to the discussion of sex differences. These measures are computed from the data on men, women and risk used in 35 scholarly works from economics, finance and decision science. The results are considerably more mixed and overlapping than would commonly be inferred from the broad claims made in the literature, with standardized differences in means mostly amounting to considerably less than one standard deviation, and the degree of overlap between male and female distributions generally exceeding 80%. In addition, studies that look at contextual influences suggest that these contribute importantly to observations of differences both between and within the sexes.     

Intangible capital in the pharmaceutical and chemical industry

We investigate whether measures of intangible capital based on advertising and R&D can explain variation in Tobin's Q ratio for the pharmaceutical and chemical industry. The study is motivated by prior literature studying this relation in other industries, recent literature investigating intangible capital in this industry, and the larger controversy about whether stock valuations have been high due to irrational investors or large investment in intangible capital. We find that our measures of intangible capital are statistically significant determinants of Q and explain 20% of the variation in our sample. When age and industry are incorporated into the model our explanatory power reaches 25%.     

Genetic distance,trade, and the diffusion of development

The determinants of countries' long‐term income differences feature prominently in the literature. Spolaore and Wacziarg (The diffusion of development, Quarterly Journal of Economics, 2009 , 124, 469–529) argue that cultural differences, measured by countries' genetic distance, are an important barrier to the diffusion of development from the world's technological frontier. We revisit their findings in three ways. First, we successfully reproduce their results and confirm the robustness of their baseline findings. Second, we estimate their models for different time periods and find that the impact of genetic distance on income differences did not significantly change over time. Finally, we explore one of the underlying mechanisms of technology adoption and show that bilateral trade is one channel through which cultural differences retard the diffusion of development.     

The effects of bargaining power on trade credit in a supply network

We develop a multi-tier supply network model, rooted in social network theory, to evaluate the effect of bargaining power on trade credit and to track the effect of buyers' trade credit on suppliers' trade credit. We apply social network analysis to measure companies' bargaining power in the supply network of Hennes & Mauritz AB (H&M, the Swedish clothing retailer). The results show that the buyer's bargaining power significantly affects the choice of trade credit, and that the supplier's “upstreamness” is significantly associated with its trade credit. We find limited evidence to support the notion of a financial bullwhip effect, a result that merits further research, since this study is limited to the network of one company up to its fourth tier of suppliers in one financial year. Our results can be applied by companies seeking to control their cash flow and, therefore, the financial pressure within their supply network. This study contributes to the literature by bringing social network measures into the buyer–supplier financial flow, as well as offering one of the first empirical examinations of the propagation of financial pressure in a multi-tier supply network.     

Towards an integrated model for the transference of environmental responsibility

This research explores how environmental responsibility transfers to others. Although environmental responsibility is one of the most debated topics in environmental management literature, a framework describing how a teacher's environmental responsibility shapes the student's environmental responsibility is still lacking. Adopting emotional contagion theory as a lens, the paper addresses this issue via the mediation of emotional contagion and the moderation of a teacher's environmental concern. Based on a survey of teachers and students (N = 283) conducted in Pakistan, our findings provide evidence that a teacher's environmental responsibility can better transfer to students via emotional contagion. Additionally, our data establish that the transference of environmental responsibility from teachers to students via emotional contagion is more effective when the teacher has a high level of environmental concern than when he or she has a low level of environmental concern. Finally, the authors discuss the implications for policy in detail.     

Racing To Invest? The Dynamics of Competition in Ethical Drug Discovery

Recent advances in the theoretical literature have greatly expanded our understanding of the forces that shape the competitive dynamics of research and development, but a paucity of sufficiently detailed empirical data has left these insights relatively untested. We draw on unusually detailed qualitative and quantitative infernal data provided at the research program level by 10 major pharmaceutical firms to explore the usefulness of the modern literature as a source of insight into the dynamics of competition in ethical drug discovery. Our analysis focuses on one particularly compelling aspect of the literature: the suggestion that in “winner take all situations,” competition in R&D becomes a Prisoner's Dilemma, leading to overinvestment in research. Without adequate measures of the social return to innovation, we can say nothing about whether there is “too much” or “too little” research undertaken by the industry, but our results do not support the suggestion that R&D investment in drug discovery is driven by the “tit-for-tat” or simple reaction function models hinted at by the institutional literature. First, R&D investment is only weakly correlated across firms once common responses to exogenous shocks are accounted far, and second, rivals' R&D results are positively correlated with own research productivity, which we interpret as evidence for extensive R&D spillovers rather than the depletion externality implied by “winner take all” models. These results are not, of themselves, sufficient to reject the hypothesis that investment behavior in the industry is driven by strategic considerations since there is theoretical support for a wide variety of observable behavior as equilibrium outcomes of strategic interaction. Nonetheless, they suggest that the more extreme forms of rent dissipation identified in the literature are probably poor characterizations of the reality of competition in pharmaceuticals. Our results point both to the need to develop theories that incorporate richer models of possible payoff structures, adjustment costs, and firm heterogeneity and to the need to collect empirical data that is comprehensive enough to enable one to test them.     

Firm-diversification effects on performance as measured by tobin's q

The performance effects of firm diversification remain unclear despite a large body of prior research that has yielded mixed results due to differing performance measures, diversification measures, samples and time periods. The objective of this research is to offer further information by using Tobin's q to capture performance effects and Rumelt's related ratio as the diversification measure. The empirical results reveal no significant findings to relate diversification and performance. Given that the sample is composed of very large firms, the implication is that, at least for such large firms whose stock is likely held in well-diversified portfolios, firm-diversification strategies are unlikely to yield superior performance.     

Realized volatility forecasting and option pricing

A growing literature advocates the use of microstructure noise-contaminated high-frequency data for the purpose of volatility estimation. This paper evaluates and compares the quality of several recently-proposed estimators in the context of a relevant economic metric, i.e., profits from option pricing and trading. Using forecasts obtained by virtue of alternative volatility estimates, agents price short-term options on the S&P 500 index before trading with each other at average prices. The agents’ average profits and the Sharpe ratios of the profits constitute the criteria used to evaluate alternative volatility estimates and the corresponding forecasts. For our data, we find that estimators with superior finite sample Mean-squared-error properties generate higher average profits and higher Sharpe ratios, in general. We confirm that, even from a forecasting standpoint, there is scope for optimizing the finite sample properties of alternative volatility estimators as advocated by Bandi and Russell [Bandi, F.M., Russell, J.R., 2005. Market microstructure noise, integrated variance estimators, and the accuracy of asymptotic approximations. Working Paper; Bandi, F.M., Russell, J.R., 2008b. Microstructure noise, realized variance, and optimal sampling. Review of Economic Studies 75, 339–369] in recent work.     

Reading Keynes' Treatise on Probability

A Treatise on Probability was published by John Maynard Keynes in 1921. The Treatise contains a critical assessment of the philosophical foundations of probability and of the statistical methodology at the time. We review the aspects of the book that are most related with statistics, avoiding uninteresting neophyte's forrays into philosophical issues. In particular, we examine the arguments provided by Keynes against the Bayesian approach, as well as the sketchy alternative of a return to Lexis' theory of analogies he proposes. Our conclusion is that the Treatise is a scholarly piece of work looking at past advances rather than producing directions for the future.     

A Multi‐Dimensional Framework of Organizational Innovation: A Systematic Review of the Literature

This paper consolidates the state of academic research on innovation. Based on a systematic review of literature published over the past 27 years, we synthesize various research perspectives into a comprehensive multi‐dimensional framework of organizational innovation – linking leadership, innovation as a process, and innovation as an outcome. We also suggest measures of determinants of organizational innovation and present implications for both research and managerial practice.     

Research productivity patterns in the organizational behavior and human resource management literature

Closely following the analysis approach used for similar studies in the economics and finance literature, we present the first study to examine if there exists an empirical regularity in the bibliometric patterns of research productivity in the organizational behavior (OB) and human resource management (HRM) literature. Our results present strong evidence that there indeed exists a distinct empirical regularity. It is the so-called Generalized Lotka's Law of scientific productivity pattern: The number of authors publishing n papers is about 1/n^c of those publishing one paper. The observed pattern in the OB and HRM area is interestingly very consistent with those in much older, related business disciplines.     

Contra Private Fairness*

This article attempts to clarify our understanding of the everyday use of the word “fair” as we apply it to economic behavior. I first examine the decomposition of fair into its semantic primitives and discuss implications of recent research that indicates that the word is one‐to‐one untranslatable into any other language, that is, the concept of fair is distinctly Anglo. I also make a Wittgensteinian appeal to context and human sociality as an indispensable tether for what we mean by a fair experience and what we know, epistemologically speaking, about fairness. The principal implication of this is that rules that guide fair behavior are not located in an individual's private utility function but instead reside in the connections that the individual has to his cultural environs.     

The Importance of Alliances in Firm Capital Structure Decisions: Evidence from Biotechnology Firms

Building on finance research, we argue that the ex post hazards arising from alliance formation depend upon the firm's financial condition. Financial distress jeopardizes the continuity of an alliance and the value of the investments involved. Thus, firms should reduce leverage to signal continued commitment and to induce investments from alliance partners. Accordingly, we find that a firm's current alliance propensity predicts its subsequent capital structure decisions and that this relationship is most pronounced in the presence of other exchange hazards. Our paper contributes to alliance research and to the growing literature discussing the strategic consequences of capital structure. Copyright © 2015 John Wiley & Sons, Ltd.