Optimal quantization applied to sliced inverse regression

In this paper we consider a semiparametric regression model involving a d-dimensional quantitative explanatory variable X and including a dimension reduction of X via an index β′X. In this model, the main goal is to estimate the Euclidean parameter β and to predict the real response variable Y conditionally to X. Our approach is based on sliced inverse regression (SIR) method and optimal quantization in L^p-norm. We obtain the convergence of the proposed estimators of β and of the conditional distribution. Simulation studies show the good numerical behavior of the proposed estimators for finite sample size.     

Wages and employment of French workers with African origin

Our study focuses on the differences in wages and employment between French workers with French parents and French workers with at least one African parent, using the Formation Qualification Professionnelle survey (Insee, Paris, 2003). We introduce econometric decompositions, which allow us to reach conclusions when the potentially discriminated group is small. Then, we clarify the impact of discrimination at the hiring level in this context. We find that unexplained parts in the employment decompositions are much larger than in the wage decompositions. This suggests that, in France, labor market discrimination is more frequent at the hiring level than in the compensation process.     

Revisiting the Structure of Subjective Well-Being in Middle-Aged Adults

Subjective well-being is a broad, multifaceted construct comprising general satisfaction with life, satisfaction with life domains (health, family, people, free time, self, housing, work, and finances), positive affect, and negative affect. Drawing on representative data from middle-aged adults (N = 738), the authors used three different structural models to analyze the interrelationships among these facets of subjective well-being. In a top-down model, a single factor representing global subjective well-being explained the correlations found among the more specific facets of subjective well-being and exerted the strongest influence on general satisfaction with life, satisfaction with health, and satisfaction with finances. In a bottom-up model, satisfaction with the latter two domains had the strongest effect on global subjective well-being. The authors discuss the implications of their findings for research on subjective well-being.     

Recruiting Arab Fathers in a Center for Children at Risk in Israel

Arab society in Israel is positioned between the traditional, collective values of Arab culture and the more prevalent Western individualistic values of the Israeli society at large. This poses a challenge for the welfare services in Israel, especially in the case of Arab clients, who tend to receive and interpret the social workers' messages as contradictory to their cultural norms. Therefore, recruiting Arab fathers for treatment is a particularly difficult task. The article focuses on creating a culturally sensitive process for recruiting Arab fathers for treatment in a center dealing with Arab families at risk in Israel.     

Nonparametric causal effects based on marginal structural models

A parametric marginal structural model (PMSM) approach to Causal Inference has been favored since the introduction of MSMs by Robins [1998a. Marginal structural models. In: 1997 Proceedings of the American Statistical Association. American Statistical Association, Alexandria, VA, pp. 1–10]. We propose an alternative, nonparametric MSM (NPMSM) approach that extends the definition of causal parameters of interest and causal effects. This approach is appealing in practice as it does not require correct specification of a parametric model but instead relies on a working model which can be willingly misspecified. We propose a methodology for longitudinal data to generate and estimate so-called NPMSM parameters describing so-called nonparametric causal effects and provide insight on how to interpret these parameters causally in practice. Results are illustrated with a point treatment simulation study. The proposed NPMSM approach to Causal Inference is compared to the more typical PMSM approach and we contribute to the general understanding of PMSM estimation by addressing the issue of PMSM misspecification.     

La distinction : addendum statistique

The aim of this study is twofold: first, to assess the statistical significance of the data used by Pierre Bourdieu in Distinction; second, to test the hypothesis that the volume of capital (i.e., the global amount of capital) allows for a finer discrimination of dispositional differences than the composition of capital (i.e., the respective weight of the different types of capital in the global amount of capital). To these ends, five data samples were submitted to bilateral between‐proportion comparison tests. The findings (1) reveal that about two‐thirds of the differences reported by P. Bourdieu are significant and (2) support the view that the volume of capital prevails over its composition. Cette étude poursuit deux objectifs : établir, d'une part, la significativité statistique des données ayant servi de base empirique au modèle que Pierre Bourdieu propose dans La distinction ; mettre à l’épreuve, d'autre part, l'hypothèse selon laquelle le volume de capital (i.e. la quantité globale de capital) constitue, en matière de différenciation dispositionnelle, une variable plus déterminante que la structure du capital (i.e. le poids respectif des différents types de capital au sein du volume global de capital). À cette double fin, les données relatives à cinq échantillons sont soumises à des tests de comparaison bilatérale de proportions indépendantes. Les résultats obtenus (1) révèlent que près des deux tiers des différences observées par P. Bourdieu sont significatives et (2) soutiennent l'hypothèse de la prépondérance du volume de capital sur sa structure.     

British Cities and Ethnic Minorities in the Post-war Era: From Xenophobic Agitation to Multi-Ethnic Government

This essay retraces the history of immigration and ethnic minority politics in British cities in the post-war era. It shows that British cities evolved in that period from an attitude of indifference and/or hostility to immigrants in the late 1950s, to the creation of race-sensitive policies in the context of a bipartisan effort to depoliticize the issue at the national level in the 1960s, and finally to increasing participation of minorities in the politics of the Labour Party from the late 1970s onward.     

The impact of Arab-Israeli culture on the characteristics of the therapeutic encounter between women social workers and fathers in Arab parent–child centers

Summary: The aim of the study was to present the impact of the Arab-Israeli culture on the therapeutic encounter between women social workers with fathers in Arab parent–child centers in Israel. The research was qualitative, and was based on in-depth interviews with 15 Arab women social workers employed in nine parent–child centers, where they treat Arab fathers. Findings: The social workers’ perceptions about the fathers’ perceptions of the therapeutic encounter has an impact on the professional encounter. In some cases, these perceptions were a hindrance to the treatment and necessitated work to help the father overcome these perceptions and to reduce his potential resistance to the treatment. In other cases, the social workers’ perceptions about the fathers’ perceptions advanced the treatment. A supportive attitude toward the treatment meant a better starting point, which was reflected throughout the therapeutic process, when the father believed in the treatment and accepted the idea of asking for help. Application: The study findings show the importance of the social workers’ awareness of the fathers’ cultural stance, as well as of the similarities and differences between their own cultural perceptions and that of the fathers.     

A new characterization of the jump rate for piecewise-deterministic Markov processes with discrete transitions

Piecewise-deterministic Markov processes form a general class of non diffusion stochastic models that involve both deterministic trajectories and random jumps at random times. In this paper, we state a new characterization of the jump rate of such a process with discrete transitions. We deduce from this result a non parametric technique for estimating this feature of interest. We state the uniform convergence in probability of the estimator. The methodology is illustrated on a numerical example.     

Temporal dynamics of inter-limb coordination in ice climbing revealed through change-point analysis of the geodesic mean of circular data

This study examined the temporal dynamics of the inter-limb angles of skilled and less skilled ice climbers to determine how they explored ice fall properties to adapt their coordination patterns during performance. We observed two circular time series corresponding to the upper- and lower-limbs of seven expert and eight inexperienced ice climbers. We analyzed these data through a multiple change-point analysis of the geodesic (or Fréchet) mean on the circle. Guided by the nature of the geodesic mean obtained by an optimization procedure, we extended the filtered derivative method, known to be computationally very cheap and fast, to circular data. Local estimation of the variability was assessed through the number of change-points computed via the filtered derivatives with p-value method for the time series and integrated squared error (ISE). Results of this change-point analysis did not reveal significant differences of the number of change-points between groups but indicated higher ISE that supported the existence of plateaux for beginners. These results emphasized higher local variability of limb angles for experts than for beginners suggesting greater dependence on the properties of the performance environment and adaptive behaviors in the former. Conversely, the lower local variance of limb angles assessed in beginners may reflect their independence of the environmental constraints, as they focused mainly on controlling body equilibrium.