Unexplored dimensions of discrimination in Europe: homosexuality and physical appearance

We study labor-market discrimination of individuals with “specific” characteristics in Italy. We conduct a field experiment in two Italian cities: Rome and Milan, by sending “fake” CVs to real ads. We find that there is a strong penalty for homosexuals, i.e., about 30 % less chance to be called back compared to a heterosexual male and even more so if they are highly skilled. On the other hand, we find no penalty for homosexual females. We also find a beauty premium for females only but this premium is much lower when the “pretty” woman is skilled.     

Maximin design on non hypercube domains and kernel interpolation

In the paradigm of computer experiments, the choice of an experimental design is an important issue. When no information is available about the black-box function to be approximated, an exploratory design has to be used. In this context, two dispersion criteria are usually considered: the minimax and the maximin ones. In the case of a hypercube domain, a standard strategy consists of taking the maximin design within the class of Latin hypercube designs. However, in a non hypercube context, it does not make sense to use the Latin hypercube strategy. Moreover, whatever the design is, the black-box function is typically approximated thanks to kernel interpolation. Here, we first provide a theoretical justification to the maximin criterion with respect to kernel interpolations. Then, we propose simulated annealing algorithms to determine maximin designs in any bounded connected domain. We prove the convergence of the different schemes. Finally, the methodology is applied on a challenging real example where the black-blox function describes the behaviour of an aircraft engine.     

Delinquent Networks

Delinquents are embedded in a network of relationships. Each delinquent decides in a non‐cooperative way how much delinquency effort he will exert. We characterize the Nash equilibrium and derive an optimal enforcement policy, called the key‐player policy. We then extend our characterization of optimal single player network removal to optimal group removal, the key group. We also characterize and derive a policy that targets links rather than players. Finally, we endogenize the network connecting delinquents by allowing players to join the labor market instead of committing delinquent offenses. The key‐player policy turns out to be much more complex because it depends on wages and on the structure of the network. (JEL: A14, C72, K42, L14)     

On multivariate separating Hill estimator under estimated location and scatter

We consider estimating the tail-index of a distribution under the assumption of multivariate ellipticity. Recently, a separating Hill estimator for multivariate elliptical distributions was proposed. This estimator is an affine invariant alternative to using the marginal observations in tail-index estimation and is hence unaffected by, e.g. change of units of measurement. However, the separating Hill estimator depends on the location and scatter of the elliptical distribution, which, in practice, have to be estimated. The effect of replacing the true location and scatter of the distribution by estimates has previously been only examined through simulations. In this article we show that the error caused by replacing the location and scatter of the distribution by estimates indeed is asymptotically negligible. This fact is essential for the practicality of the separating Hill estimator. In addition to providing the theoretical results, we present simulation results on the asymptotic behaviour of the estimators.     

Bain: a program for Bayesian testing of order constrained hypotheses in structural equation models

This paper presents a new statistical method and accompanying software for the evaluation of order constrained hypotheses in structural equation models (SEM). The method is based on a large sample approximation of the Bayes factor using a prior with a data-based correlational structure. An efficient algorithm is written into an R package to ensure fast computation. The package, referred to as Bain, is easy to use for applied researchers. Two classical examples from the SEM literature are used to illustrate the methodology and software.     

Constructing merit in the civil service: The French Ministry of Culture (1880–1980)

Merit-based procedures for evaluation and grading in the French Civil Service have often been studied with the idea that concepts and practices circulate between public and private sectors, domestic and foreign organizations. Less attention has been afforded the in-house origins of procedures for assessing the work of civil servants. This article focuses on the procedures gradually built up to evaluate government employees in the French Ministry of Culture. Light is shed on the difficulties of making good the Republic's promise to base merit on differences in talent alone. How is a civil servant's work to be measured? Are qualifications evaluated while seeing to it that as many employees as possible can be promoted? Focusing on procedures – imagined or actually implemented – for grading, evaluating and promoting museum personnel shows that the process follows a timing and modality that vary depending on one's position in the hierarchy. The evaluation process nevertheless creates ties between socio-occupational groups that all else separates. Ways to measure civil servants’ activity existed before the neomanagerial objection to bureaucratic rules and regulations of the 1960s; the French system for evaluating merit is, thus, not simply an importation of anglo-saxon managerial methods.     

A class of nonparametric tests for location and scale parameters

A class of nonparametric two-sample tests for testing identity of distributions versus alternatives containing both location and scale parameters is proposed and some properties are derived. A recursion formula for the exact distribution under the hypothesis is presented and, the asymptotic distribution is given under both the hypothesis and a contiguous sequence of alternatives. Some asymptotic optimality properties are deduced for particular tests of the class and finally, the asymptotic efficiency is found.     

Propensity score applied to survival data analysis through proportional hazards models: a Monte Carlo study

Propensity score methods are increasingly used in medical literature to estimate treatment effect using data from observational studies. Despite many papers on propensity score analysis, few have focused on the analysis of survival data. Even within the framework of the popular proportional hazard model, the choice among marginal, stratified or adjusted models remains unclear. A Monte Carlo simulation study was used to compare the performance of several survival models to estimate both marginal and conditional treatment effects. The impact of accounting or not for pairing when analysing propensity‐score‐matched survival data was assessed. In addition, the influence of unmeasured confounders was investigated. After matching on the propensity score, both marginal and conditional treatment effects could be reliably estimated. Ignoring the paired structure of the data led to an increased test size due to an overestimated variance of the treatment effect. Among the various survival models considered, stratified models systematically showed poorer performance. Omitting a covariate in the propensity score model led to a biased estimation of treatment effect, but replacement of the unmeasured confounder by a correlated one allowed a marked decrease in this bias. Our study showed that propensity scores applied to survival data can lead to unbiased estimation of both marginal and conditional treatment effect, when marginal and adjusted Cox models are used. In all cases, it is necessary to account for pairing when analysing propensity‐score‐matched data, using a robust estimator of the variance. Copyright © 2012 John Wiley & Sons, Ltd.     

Simple random sampling with over-replacement

There are several ways to select units with replacement and an equal inclusion expectation. We present a new sampling design called simple random sampling with over-replacement. Its interest lies in the high variance produced for the Horvitz-Thompson estimator. This characteristic could be useful for resampling methods.