The contribution of network research to managerial culture and practice

Although research on social networks has gained significant influence in the academic world, several factors seem to have lowered its echo in the business world. It is still unclear how this fast-growing stream of research has translated into solid implications for managerial action and decision making. Based on a review of recent research, this paper attempts to provide evidence that network research does have practical relevance. We focus on five areas where network research has introduced new angles and renewed the understanding of how organizations should tackle management issues. We also suggest directions for future research, with the same objective of placing the emphasis on strengthening the contribution of the approach to management practices.     

Ergonomic investigation on pedestrian crossing with traffic light signalization

This article is about the risk behavior adopted by pedestrians at crosswalks with traffic light equipment. It was observed that many pedestrians take risk to cross the Presidente Vargas Avenue. This avenue is located in downtown in Rio de Janeiro city, Brazil, and has a heavy vehicular traffic and intense pedestrian flow. Many pedestrians cross the four lanes of avenue dangerously disobeying the traffic light indications. To conduct this research about pedestrian's behavior at crosswalks, a model known as Communication-Human Information Processing Model - C-HIP Model was used. Investigating the stages by C-HIP model perspective, using methods and techniques for each stage, enabled to identify which factors can contribute to pedestrians to disobey traffic signs and adopt a risky behavior in pedestrian crossing.     

The Law of Large Demand for Information

An unresolved problem in Bayesian decision theory is how to value and price information. This paper resolves both problems assuming inexpensive information. Building on Large Deviation Theory, we produce a generically complete asymptotic order on samples of i.i.d. signals in finite–state, finite–action models. Computing the marginal value of an additional signal, we find it is eventually exponentially falling in quantity, and higher for lower quality signals. We provide a precise formula for the information demand, valid at low prices: asymptotically a constant times the log price, and falling in the signal quality for a given price.     

A developmental perspective of gambling behavior in children and adolescents

Although it has been determined that gambling is a popular activity amongst the young, there seems to be a lack of studies examining developmental differences in children's gambling behavior. This study examines developmental differences in children's blackjack gambling behavior. One hundred and four students (51 males; 53 females) from grades 4, 6, and 8 completed a questionnaire examining their gambling behavior in general and individually played a computerized blackjack game with the following data being recorded: percentage of accuracy, amounts of money bet, gross winnings, percentage of wins, number of hands played, and end balance. Findings revealed few developmental differences in prevalence and frequency of gambling behavior and performance on a blackjack task. Males were found to wager greater amounts of money and have larger gross winnings than females on the blackjack task. Furthermore, males were more likely to view gambling as involving both large amounts of skill and luck, thus suggesting an illusion of control for gambling activities. The results are discussed from a cognitive developmental perspective.This research was partially supported by a grant from the McGill University Social Science Computer Committee. The authors would like to thank the administration, staff, and students in T.H. Bowes, Prince Charles, Souvenir, Gerald McShane, Our Lady of Pompei, Pierrefond Comprehensive High School, and Western Laval High School, for their participation and cooperation in this study.This is a revision of a paper presented at the Ninth International Conference on Gambling and Risk-Taking, Las Vegas, 1994.     

Measuring cross-country technological catch-up through variable-parameter FDH

In this paper, we estimate indices of technological catch-up for a sample of 52 countries through the FDH approach with variable scaling parameters proposed in Kerstens and Vanden Eeckaut (1999). We show that this technique has significant advantages for the international comparisons of productivity and, more generally, wherever the assumption of convexity for the production set is not likely to be appropriate. We want to thank Laurens Cherchye, Hal Fried, Kristian Kerstens and an anonymous referee for useful comments on preceding versions of this paper. The usual disclaimer applies. Financial support from the MURST, Italy, is gratefully acknowledged.     

A non-linear time series approach to modelling asymmetry in stock market indexes

In this paper we analyse the performances of a novel approach to modelling non-linear conditionally heteroscedastic time series characterised by asymmetries in both the conditional mean and variance. This is based on the combination of a TAR model for the conditional mean with a Constrained Changing Parameters Volatility (CPV-C) model for the conditional variance. Empirical results are given for the daily returns of the S&P 500, NASDAQ composite and FTSE 100 stock market indexes.     

BL-GARCH models and asymmetries in volatility

In this paper the class of Bilinear GARCH (BL-GARCH) models is proposed. BL-GARCH models allow to capture asymmetries in the conditional variance of financial and economic time series by means of interactions between past shocks and volatilities. The availability of likelihood based inference is an attractive feature of BL-GARCH models. Under the assumption of conditional normality, the log-likelihood function can be maximized by means of an EM type algorithm. The main reason for using the EM algorithm is that it allows to obtain parameter estimates which naturally guarantee the positive definiteness of the conditional variance with no need for additional parameter constraints. We also derive a robust LM test statistic which can be used for model identification. Finally, the effectiveness of BL-GARCH models in capturing asymmetric volatility patterns in financial time series is assessed by means of an application to a time series of daily returns on the NASDAQ Composite stock market index.     

Simulation analysis of cold chain performance based on time–temperature data

Perishable goods are a fundamental source of revenue for the retail sector; their management, however, constitutes a severe challenge for retailers and supply chain partners. A significant cost in particular is the fraction of products perished through the supply chain, which also constitutes an ethical and environmental concern. Supply chain organisation and operative characteristics have a significant influence on this matter, as in fact ensuring suitable temperature conditions for the stock-keeping units throughout the supply chain is mandatory for perishable products. Recent developments in sensing and communication technologies allow detailed monitoring and control of cold chain; however, depending on the characteristics of the supply chain, an inherent risk of perished products is often inevitable, even in the hypothesis of perfect control. This article proposes a methodology to evaluate the performance of a cold chain in terms of expected product quality at the retail store, and to estimate the expected fraction of perished products, according to the supply chain configuration. The approach is based on Monte Carlo simulation, and implements referenced shelf-life models. A real application is also presented, involving a preliminary analysis and mapping of the supply chain activities based on time–temperature data, in order to demonstrate the practicability of the approach proposed.