Normes,théorie des jeux et pratiques participatives: le poids réel des travailleurs dans les économies libérales

Les auteurs analysent l'effet de la directive européenne relative à l'information et à la consultation des travailleurs sur les pratiques participatives en entreprise au Royaume‐Uni et en Irlande. Dans une analyse conceptuelle et empirique, qui fait appel à la théorie des jeux, ils formulent trois hypothèses explicatives, qu'ils cherchent à vérifier avec des données qualitatives recueillies auprès de seize entreprises. La démonstration permet de comprendre pourquoi la coopération, gage de gains mutuels, n'est pas la solution qui l'emporte dans les pays examinés, et elle nous en dit un peu plus sur l'effet des normes sur la gestion participative dans les économies de marché libérales.     

Estimating population characteristics by incorporating prior values in stratified random sampling/ranked set sampling

In this paper, we discuss the estimation of population characteristics using stratified random sampling in an infinite population framework, including ranked set sampling as a special case. The use of prior values is considered and the underlying distribution is assumed to be unknown. The estimator considered in each stratum is the weighted mean of the U-statistic and prior value. The optimum weight is obtained by minimizing the mean squared error of the estimator of the population characteristics, but it contains unknown parameters and those parameters are replaced with their estimates. Simulation results show the gains in efficiency of the proposed estimator, yielding gains of at least 1.2 times larger than the usual unbiased estimator under certain condition specified in the text. Guidelines for the usage of the proposed estimator are shown and an application to a real data set is provided.     

“The Young Ones are the Condom Generation”: Condom Use amongst Out-of-School Adolescents in Rural Southwest Uganda

This article reports on factors influencing condom use among out-of-school adolescents in rural southwest Uganda. Despite an abundance of negative discourses and myths about condoms in the community, these adolescents believe condoms protect them from sexually transmitted infections, HIV, and premarital pregnancies. Girls want partners to use condoms, but most lack the confidence to insist. Girls aged 13 to 14 reported the least difficulty asking for condoms; older girls attributed this to coming-of-age in the era of AIDS when condom use is the norm. Boys under 16 years want to use condoms, but lack confidence in application skills. Boys over 17 years always use condoms with casual partners, but only occasionally for pregnancy prevention with steady partners. Girls need skills training to improve confidence in negotiating condom use. Younger boys require training to improve confidence in skills with condom application. These findings are compared with studies conducted with in-school adolescents in the same study area. Health promotions that provide this skills training and focus on the need to think of the health of future family would be most effective for out-of-school adolescents. This study shows that it is self-confidence, rather than years of schooling, that has the greatest impact on condom use in this cohort.     

OBTAINING AND PARAMETERIZING MULTIPERIOD PORTFOLIOS WITH DESIRABLE CHARACTERISTICS UNDER LOGNORMAL RETURNS

The expected geometric mean has been shown to be a valuable criterion in ranking portfolios of assets. For example, under certain conditions the maximum expected geometric-mean portfolio minimizes the expected time to amass a fixed level of wealth as wealth becomes “large.” This paper develops a simple algorithm for obtaining such portfolios when portfolio returns are assumed to be lognormally distributed. The risk-return characteristics of portfolios are derived and illustrated using data from a subset of stocks found on the New York Stock Exchange.     

Generalized modified slash distribution with applications

Abstract

In this article a generalization of the modified slash distribution is introduced. This model is based on the quotient of two independent random variables, whose distributions are a normal and a one-parameter gamma, respectively. The resulting distribution is a new model whose kurtosis is greater than other slash distributions. The probability density function, its properties, moments, and kurtosis coefficient are obtained. Inference based on moment and maximum likelihood methods is carried out. The multivariate version is also introduced. Two real data sets are considered in which it is shown that the new model fits better to symmetric data with heavy tails than other slash extensions previously introduced in literature.     

Adaptive methods for sequential importance sampling with application to state space models

In this paper we discuss new adaptive proposal strategies for sequential Monte Carlo algorithms—also known as particle filters—relying on criteria evaluating the quality of the proposed particles. The choice of the proposal distribution is a major concern and can dramatically influence the quality of the estimates. Thus, we show how the long-used coefficient of variation (suggested by Kong et al. in J. Am. Stat. Assoc. 89(278–288):590–599, 1994) of the weights can be used for estimating the chi-square distance between the target and instrumental distributions of the auxiliary particle filter. As a by-product of this analysis we obtain an auxiliary adjustment multiplier weight type for which this chi-square distance is minimal. Moreover, we establish an empirical estimate of linear complexity of the Kullback-Leibler divergence between the involved distributions. Guided by these results, we discuss adaptive designing of the particle filter proposal distribution and illustrate the methods on a numerical example. This work was partly supported by the National Research Agency (ANR) under the program “ANR-05-BLAN-0299”.     

The paths embedding of the arrangement graphs with prescribed vertices in given position

Let n and k be positive integers with n?k≥2. The arrangement graph A _n,k is recognized as an attractive interconnection networks. Let x, y, and z be three different vertices of A _n,k . Let l be any integer with $d_{A_{n,k}}(\mathbf{x},\mathbf{y}) \le l \le \frac{n!}{(n-k)!}-1-d_{A_{n,k}}(\mathbf{y},\mathbf{z})$ . We shall prove the following existance properties of Hamiltonian path: (1)?for n?k≥3 or (n,k)=(3,1), there exists a Hamiltonian path R(x,y,z;l) from x to z such that d _R(x,y,z;l)(x,y)=l; (2) for n?k=2 and n≥5, there exists a Hamiltonian path R(x,y,z;l) except for the case that x, y, and z are adjacent to each other.     

RENT CREATION AND RENT SHARING: NEW MEASURES AND IMPACTS ON TOTAL FACTOR PRODUCTIVITY

This analysis proposes new measures of rent creation and rent sharing and assesses their impact on productivity on cross‐country‐industry panel data. We find first that: (1) anticompetitive product market regulations positively affect rent creation and (2) employment protection legislation boosts hourly wages, particularly for low‐skill workers. However, we find no significant impact of this employment legislation on rent sharing, as the hourly wage increases are offset by a negative impact on hours worked. Second, using regulation indicators as instruments, we find that rent creation and rent sharing both have a substantial negative impact on total factor productivity. (JEL E22, E24, O30, L50, O43, O47, C23)     

Modified skew-slash distribution

Abstract

In this work, we introduce a new skewed slash distribution. This modification of the skew-slash distribution is obtained by the quotient of two independent random variables. That quotient consists on a skew-normal distribution divided by a power of an exponential distribution with scale parameter equal to two. In this way, the new skew distribution has a heavier tail than that of the skew-slash distribution. We give the probability density function expressed by an integral, but we obtain some important properties useful for making inferences, such as moment estimators and maximum likelihood estimators. By way of illustration and by using real data, we provide maximum likelihood estimates for the parameters of the modified skew-slash and the skew-slash distributions. Finally, we introduce a multivariate version of this new distribution.