Bootstrapping Confidence Intervals for Linear Programming Efficiency Scores: With an Illustration Using Italian Banking Data

This article suggests a method for introducing a stochastic element into Farrell measures of technical efficiency as calculated via linear programming techniques. Specifically, a bootstrap of the original efficiency scores is performed to derive confidence intervals and a measure of bias for the scores. The bootstrap generates these measures of statistical precision for the nonstochastic efficiency measures by using computational power to derive empirical distributions for the efficiency measures.     

Gini's “Transvariazione” and the measurement of distance between distributions

This paper notes that Gini's concept of Transvariazione corresponds to the idea of overlapping of distributions. It shows that this concept is implicit in some measures of income inequality such as the Pietra and Gini Index and is at the basis of various measures of distance between distributions. An empirical illustration is provided, based on Israeli data for the period 1978–1994.     

Prudence and precautionary saving

Households save income for various reasons, including the need to plan for the future, the intention to leave a bequest, and the desire to guard against unforeseen expenditures and income fluctuations. Although it is widely believed that prudent individuals engage in precautionary saving, the extent of such saving is not well understood. This paper develops a model of saving with an explicit role for the Leland-Kimball measure of prudence. Estimation of the model using household-level data from Italy suggests an average value of relative prudence near 4 or 5, with approximately 15 to 36 percent of total saving being precautionary. The authors are grateful to an anonymous referee for helpful comments.     

The Journal of Risk and Insurance: A 75-Year Historical Perspective

This research provides a comprehensive historical analysis of articles published in The Journal of Risk and Insurance over the 75‐year period from 1932 to 2006. Historical statistics are provided including the number of articles, number of authors per article, geographic location of contributors, leading contributors, author affiliation (industry or academic), the proportion of articles that are theoretical and empirical, and topics covered. Statistics relating to the entire 75‐year period are provided as well as breakdowns by decade. The results indicate that the contributors to The Journal of Risk and Insurance have become more international over time, average article length and average number of authors per article have increased over time, and empirical articles appear more frequently than theoretical articles.     

Empirically based modeling in financial economics and beyond, and spurious stylized facts

The discovery of the dynamics of a time series requires construction of the transition density. We explain why 1-point densities and scaling exponents cannot determine the class of stochastic dynamics. Time series require some sort of underlying statistical regularity to provide a basis for analysis, and we construct an exhaustive list of such tests. The condition for stationary increments, not scaling, determines the existence of long time pair autocorrelations. We conjecture that for a selfsimilar process neither the pair correlations 〈x(t)x(s)〉 nor the 2-point density scales in both times t and s except in a pathological case, and give examples using three well-known Gaussian processes. An incorrect assumption of stationary increments can generate spurious stylized facts, including fat tails. When a sliding window is applied to nonstationary, uncorrelated increments then a Hurst exponent H_s = 1 / 2 is generated by that procedure even if the underlying model scales with a Hurst exponent H ≠ 1/2. We explain how this occurs dynamically. The nonstationarity arises from systematic unevenness in the traders' behavior in real time. Spurious stylized facts arise mathematically from using a log increment with a ‘sliding window’ to read the series. In addition, we show that nonstationary processes are generally not globally transformable to stationary ones. We also present a more detailed explanation of our recent FX data analysis and modeling.     

A comparative analysis of proxies for an optimal leverage ratio

Previous studies that test the tradeoff theory commonly use one of the following debt ratio measures to proxy for a firm's hypothesized optimal ratio: firm's time-series mean leverage, moving average leverage based on a firm's historical debt ratios, industry median leverage, and predicted leverage ratio based on cross-sectional regressions. We find that these alternative proxies yield results that are significantly different from each other. Further, regression results of models that use the optimum target leverage and the conclusions drawn from the findings are sensitive to the model's proxy. Of the proxies that are commonly used in the literature, the moving average debt measure exhibits characteristics that are most consistent with the theoretical optimal leverage ratio.     

Comparing Malta and USA police officers’ individual and organizational support on outcomes

This paper investigates the quality of support for police officers in the USA and Malta to use as protection against stress. The authors found a significantly different organizational work context for police officers doing the same tasks. Police officers in both countries would benefit from upskilling in psychological capital and police managers require upskilling in management training as a means of increasing support for police to reduce the impact of stress.     

Corporate jets and private meetings with investors

We use corporate jet flight patterns to identify private meetings with investors that are ex ante unobservable to non-participants. Using approximately 400,000 flights, we proxy for private meetings with “roadshows,” defined as three-day windows that include flights to money centers and to non-money centers in which the firm has high institutional ownership. Roadshows exhibit greater abnormal stock reactions, analyst forecast activity, and absolute changes in local institutional ownership than other flight activity. We also find positive trading gains in firms with more complex information and infrequent private meetings, suggesting that roadshows provide participating investors an advantage over non-participating investors.