A Graphical Tool for Interpreting Regression Coefficients of Trinomial Logit Models

Multinomial logit (also termed multi-logit) models permit the analysis of the statistical relation between a categorical response variable and a set of explicative variables (called covariates or regressors). Although multinomial logit is widely used in both the social and economic sciences, the interpretation of regression coefficients may be tricky, as the effect of covariates on the probability distribution of the response variable is nonconstant and difficult to quantify. The ternary plots illustrated in this article aim at facilitating the interpretation of regression coefficients and permit the effect of covariates (either singularly or jointly considered) on the probability distribution of the dependent variable to be quantified. Ternary plots can be drawn both for ordered and for unordered categorical dependent variables, when the number of possible outcomes equals three (trinomial response variable); these plots allow not only to represent the covariate effects over the whole parameter space of the dependent variable but also to compare the covariate effects of any given individual profile. The method is illustrated and discussed through analysis of a dataset concerning the transition of master’s graduates of the University of Trento (Italy) from university to employment.     

A Note on the Role of the Propensity Score for Estimating Average Treatment Effects

Hahn [Hahn, J. (1998). On the role of the propensity score in efficient semiparametric estimation of average treatment effects. Econometrica 66:315-331] derived the semiparametric efficiency bounds for estimating the average treatment effect (ATE) and the average treatment effect on the treated (ATET). The variance of ATET depends on whether the propensity score is known or unknown. Hahn attributes this to “dimension reduction.” In this paper, an alternative explanation is given: Knowledge of the propensity score improves upon the estimation of the distribution of the confounding variables.     

Les transformations de l'intégration par l'emploi: Regards croisés : France métropolitaine - île de La Réunion

Against a background of mass unemployment and the increasing precariousness of employment, the current changes in the labour market demand that we examine the previously central role of paid employment in social integration. If the individual now deprived of employment or having a temporary contract is by dint of this fact less included in society or is less secure by not having a permanent salary, is it to say that he embodies the face of the de-affiliated, of those who miss out on social benefits? Taking the example of the Reunion Island which has the highest level of unemployment and population covered by the minimum income (RMI: Revenu Minimum d'Insertion) in the country, this article endeavours to explain and understand how, in the context of a protective society and increasingly flexible employment market, new methods of social integration without and resulting from paid employment are being formed.     

20世纪三四十年代宁夏水利建设述论

20世纪三四十年代 ,宁夏地方当局等推出一系列水利建设措施 ,这既意味着宁夏水利事业的近代化开始初露端倪 ,也促使宁夏平原农田引黄灌溉得以延续 ,并对宁夏地方经济的恢复、初兴与抗日战争等具有促进作用     

Les agriculteurs dans la fabrique d'une nouvelle agriculture

The model of development that has governed the modernization of farming in France is increasingly coming under attack. Given this, analysing the “work” that farming performs to “translate” the criticisms with which it must cope in formulating new definitions of roles is important in order to understand changes under way in this sector. The changes undergone by farming over the past eighty years are briefly presented and then the procedures and results of a survey, conducted during the mad cow disease among beef-farmers in Burgundy, are described. Light is thus shed on the diversity of the positions that farmers have adopted with regard to the future of their occupation. An interpretation is proposed of how the distribution (and interplay between) these positions might affect agriculture. - Special issue on Agriculture and food.     

Marital Conflict,Ineffective Parenting,and Children's and Adolescents' Maladjustment

Data from the 1988 National Survey on Families and Households were analyzed to examine the associations among marital conflict, ineffective parenting, and children's and adolescents' maladjustment. Parents' use of harsh discipline and low parental involvement helped explain the connection between marital conflict and children's maladjustment in children aged 2 through 11. Parent‐child conflict was measured only in families with a target teenager and also was a significant mediator. Although ineffective parenting explained part of the association between marital conflict and children's maladjustment, independent effects of marital conflict remained in families with target children aged 2 through 11 (but not for families with a teenager). With a few exceptions, this pattern of findings was consistent for mothers' and fathers' reports, for daughters and sons, for families with various ethnic backgrounds, and for families living in and out of poverty.     

我国产业间波及效应的探讨

从理论上来说,某一产业的变化会引起其它产业间的连锁反映。产业间的波及效应可以通过投入系数表来加以分析。通过实证分析,研究我国产业间波及效应的强弱,可以为国家制定产业政策、优化产业结构提供依据。     

A circular-cone test for testing homogeneity against a simple tree order

Several methods exist for the problem of testing the equality of several treatments against the one-sided alternative that the treatments are better than the control. These methods include Dunnett's test, Bartholomew's likelihood-ratio test, the Abelson-Tukey-Schaafsma-Smid optimal-contrast test, and the multiple-contrast test of Mukerjee, Robertson, and Wright. A new test is proposed based on an approximation of the likelihood-ratio test of Bartholomew. This test involves using a circular cone in place of the alternative-hypothesis cone. The circular-cone test has excellent power characteristics similar to those of Bartholomew's test. Moreover, it has the advantages of being simpler to compute and may be used with unequal sample sizes.     

On the preservation of copula structure under truncation

The author characterizes the copula associated with the bivariate survival model of Clayton (1978) as the only absolutely continuous copula that is preserved under bivariate truncation.     

De minimis and equity in risk

Indices and orderings are developed for evaluating alternative strategies in the management of risk. They reflect the goals of reducing individual and collective risks, of increasing equity, and of assigning priority to the reduction and to the equity of high risks. Individual risk is defined as the (random or non-random) level of exposure to a danger. In particular the role of a lower negligibility level is investigated. A class of indices is proposed which involves two parameters, a negligibility level and a parameter of inequality aversion, and several interpretations of the indices are discussed. We provide a set of eight axioms which are necessary and sufficient for this class of indices, and we present an approach to deal with partial information on the parameters.