Noisy Contagion Without Mutation

In a local interaction game agents play an identical stage game against their neighbours over time. For nearest neighbour interaction, it is established that, starting from a random initial configuration in which each agent has a positive probability of playing the risk dominant strategy, a sufficiently large population coordinates in the long-run on the risk dominant equilibrium almost surely. Our result improves on Blume (1995), Ellison (2000), and Morris (2000) by showing that the risk dominant equilibrium spreads to the entire population in a two dimensional lattice and without the help of mutation, as long as there is some randomness in the initial configuration.     

The Effect of Diversification on Tail Risk: Evidence from US Equity Mutual Fund Portfolios

This paper examines the effect of diversification on the tail risk of US equity mutual fund portfolios by utilizing classical higher‐moment measures and robust tail weight measures. Empirical results show that market standard portfolios based on the mean‐variance framework are exposed to greater tail risk than benchmark portfolios are and diversification further intensifies this exposure.     

Climate Policy Under Fat-Tailed Risk: An Application of Dice

Uncertainty plays a significant role in evaluating climate policy, and fat-tailed uncertainty may dominate policy advice. Should we make our utmost effort to prevent the arbitrarily large impacts of climate change under deep uncertainty? In order to answer to this question, we propose a new way of investigating the impact of (fat-tailed) uncertainty on optimal climate policy: the curvature of the optimal carbon tax against the uncertainty. We find that the optimal carbon tax increases as the uncertainty about climate sensitivity increases, but it does not accelerate as implied by Weitzman’s Dismal Theorem. We find the same result in a wide variety of sensitivity analyses. These results emphasize the importance of balancing the costs of climate change against its benefits, also under deep uncertainty.     

Wage differentials by sector and gender: a quantile analysis for the Spanish case

This paper analyses existing wage differentials between workers in the public and private sectors and by gender in Spain. This analysis is run throughout the entire earnings distribution and observed wage differentials are decomposed into a part explained by differences in productive characteristics and a part due to differences in returns to such characteristics. Our results show that public sector workers tend to earn higher wages than private employees, although most of this sector wage gap is due to better public workers’ productive characteristics. A wage premium in favour of men is also found in both the public and private sectors, with the gender wage gap greater at the top of the earnings distribution.     

Assignment maximization

We evaluate the goal of maximizing the number of individuals matched to acceptable outcomes. We present two mechanisms that maximize assignments. The first is Pareto efficient and undominated—in terms of the number of assignments—in equilibrium. The second is fair for unassigned agents and assigns weakly more agents than any stable mechanism in equilibrium.     

Is it important to consider the jump component for pricing and hedging short‐term options?

The usefulness of the jump component for pricing and hedging short‐term options is studied for the KOSPI (Korean Composite Stock Price Index) 200 Index options. It is found that jumps have only a marginal effect and stochastic volatility is of the most importance. There is evidence of jumps in the underlying index but no evidence of jumps in the corresponding index options. However, these results may not be valid for individual equity options. © 2005 Wiley Periodicals, Inc. Jrl Fut Mark 25:989–1009, 2005     

Frequency Domain Tests for Residual Serial Correlation in Cointegration Regressions

This paper introduces tests for residual serial correlation in cointegrating regressions. The tests are devised in the frequency domain by using the spectral measure estimates. The asymptotic distributions of the tests are derived and test consistency is established. The asymptotic distributions are obtained by using the assumptions and methods that are different from those used in Grenander and Rosenblatt (1957) and Durlauf (1991). Small-scale simulation results are reported to illustrate the finite sample performance of the tests under various distributional assumptions on the data generating process. The distributions considered are normal and t-distributions. The tests are shown to have stable size at sample sizes as large as 50 or 100. Additionally, it is shown that the tests are reasonably powerful against the ARMA residuals. An empirical application of the tests to investigate the ‘weak-form’ efficiency in the foreign exchange market is also reported.     

On the joint production of research and training

Universities and research institutions have the responsibility to produce science and to provide training to new generations of researchers. In this paper, we propose a model to analyze the determinants of a senior scientist’s decisions about allocating time between these tasks. The results of this decision depend upon the characteristics of the research project, the senior scientist’s concern for training and the expected innate ability of the junior scientist involved. We analyze the role that a regulator can play in defining both the value of scientific projects and the future population of independent scientists.     

Social media analytics for enterprises: Typology,methods, and processes

This article provides an overview of social media analytics for managers that seek to utilize the practice for social media intelligence. Currently, managers are challenged to analyze an abundance of social media data but lack a framework within which to do so. Toward this end, this article presents a simple typology of social media analytics for enterprises. It also discusses various analytics methods for social media data. Then, this article discusses management processes of social media analytics for enterprises. An illustration of social media analytics is provided with real-world consumer review data. Finally, four challenges are discussed.     

Analysis of the promotion of cigarettes at the point of sale and its attractiveness to children

Smoking habit seriously affects public health in a number of direct and indirect ways. The study reported here took place in Brazil and examined the promotional activities of the tobacco industry at the point of sale, with particular reference to their impact on children. Tobacco control policies are generally in place in developed countries, and smokers typically develop the habit while still young. Trained researchers visited a stratified sample of 429 retail outlets in the city of São Paulo, comprising the local equivalents of bars, snack bars, luncheonettes and pubs. Data for analysis were collected by direct observation at the point of sale and interviews with the person deemed to be in charge of the outlet visited. The results indicate that the tobacco industry is displaying its products within full view of children and making use of the sales' incentives offered to the retailer. The findings contribute significantly to the study of the effect of promotion at the point of sale on young smokers and can inform the policy debate on the increasing regulation of tobacco marketing promotional methods.