二阶常微分方程边值问题

本文通过对非线性常微分方程两边边值问题：ｘ〃＝ｆ（ｔ,ｘ,ｘ’）,ｘ（０）＝Ａ,ｘ（１）＝Ｂ的解的先验估计,并利用Ｌｅｒａｙ－Ｓｃｈａｕｄｅｒ度理论讨论了解的存在性及唯一性。     

Likelihood Factorizations for Mixed Discrete and Continuous Variables

Some general remarks are made about likelihood factorizations, distinguishing parameter-based factorizations and concentration-graph factorizations. Two parametric families of distributions for mixed discrete and continuous variables are discussed. Conditions on graphs are given for the circumstances under which their joint analysis can be split into separate analyses, each involving a reduced set of component variables and parameters. The result shows marked differences between the two families although both involve the same necessary condition on prime graphs. This condition is both necessary and sufficient for simplified estimation in Gaussian and for discrete log linear models.     

Promouvoir le pouvoir collectif des travailleurs dans les réseaux de production mondialisés: retour sur une occasion manquée

L'auteur s'interroge sur la capacité des ONG de renforcer le pouvoir collectif du travail au sein des réseaux de production mondialisés en utilisant leur pouvoir de pression sur les multinationales pour lancer des programmes d'élections de comités de travailleurs dans les usines. Sur la base d'une enquête empirique menée entre 2012 et 2019 dans le sud de la Chine, il montre que ces programmes ont permis de sensibiliser les travailleurs à l'action collective et de renforcer leur agentivité, mais que l'inégalité structurelle du système de production, l'absence de protection institutionnelle en faveur des représentants élus et le durcissement du régime ont empêché qu'ils perdurent.     

Liberté syndicale et négociation collective dans l'économie des plateformes: de la mobilisation des travailleurs à l'approche axée sur les droits de l'homme

L'étude porte sur l'exercice de la liberté syndicale et du droit de négociation collective dans l'économie des plateformes. Après avoir commenté plusieurs exemples de mobilisation collective des travailleurs des plateformes dans le monde, l'auteur plaide pour l'adoption d'une approche axée sur les droits de l'homme de ces deux garanties, que divers instruments internationaux consacrent, et que de nombreux tribunaux nationaux et internationaux ont utilisées pour justifier leurs décisions. C'est pour lui la seule façon de protéger tous les travailleurs, indépendamment de leur situation au regard de l'emploi, dans un monde du travail en mutation.     

Asymptotically optimal Berry-Esseen-type bounds for distributions with an absolutely continuous part

Recursive and closed form upper bounds are offered for the Kolmogorov and the total variation distance between the standard normal distribution and the distribution of a standardized sum of n independent and identically distributed random variables. The method employed is a modification of the method of compositions along with Zolotarev's ideal metric. The approximation error in the CLT obtained vanishes at a rate O(n^−k/2+1), provided that the common distribution of the summands possesses an absolutely continuous part, and shares the same k−1 (k?3) first moments with the standard normal distribution. Moreover, for the first time, these new uniform Berry-Esseen-type bounds are asymptotically optimal, that is, the ratio of the true distance to the respective bound converges to unity for a large class of distributions of the summands. Thus, apart from the correct rate, the proposed error estimates incorporate an optimal asymptotic constant (factor). Finally, three illustrative examples are presented along with numerical comparisons revealing that the new bounds are sharp enough even to be used in practical statistical applications.     

Réinterroger la relation entre école et mobilité sociale. Le cas des enfants d’agriculteurs et d’ouvriers dans l’Ouest

Till now, the relation between schooling and social mobility, a classical question in the sociology of education, has been approached through analyses of a structural sort, either by focusing on the functions that schools are supposed to fill or by adopting the timeless model of neoclassical economics. This approach does not examine all possible relations between schools and social mobility; nor does it see these relations in terms of a process. A study of the scholastic biographies of the children of farmers and workers in western France renews our conception of this relation. It shows that this relation mainly stems from a combination of quite heterogeneous elements, which we glimpse in these biographies.     

Législation sur la protection de l'emploi et stabilité des emplois: une analyse transversale en Europe

S'appuyant sur les données d'Eurostat pour la période 1999–2006, les auteurs étudient l'évolution de l'ancienneté dans l'emploi des salariés de l'Union européenne. Ils n'observent pas de baisse généralisée de cette ancienneté, mais un raccourcissement tendanciel parmi les jeunes travailleurs (15–24 ans) dans de nombreux pays. Leurs résultats montrent que cette tendance est associée à une plus faible protection de l'emploi conférée et par le droit et par la présence de syndicats. Etant donné le faible pouvoir de négociation individuelle des jeunes travailleurs, la tendance à une plus forte individualisation des relations d'emploi pourrait, en effet, plus particulièrement les toucher.     

Reforming against all odds: Multi‐pillar pension systems in the Czech Republic and Romania

Attempts to replace pay‐as‐you‐go pension schemes with private funded systems came to a halt in Central and Eastern Europe after 2005. However, more recently, the region has witnessed two belated reformers: the Czech Republic and Romania. Both countries decided to partially privatize pensions despite the rising tide of evidence concerning the challenges associated with the policy. We argue that while part of the domestic political elite remained supportive of private funded pensions, the difficulties experienced by earlier reformers and reduced support from International Financial Institutions led to the adoption of small funded pension pillars. Such cautious attempts at privatization might become more common in the future as large reforms have proven politically unsustainable.     

A call for more elaborate and transparent pension data to inform policy‐making: A critical examination of World Bank data for Eastern Europe

This article offers a critical analysis of the methods by means of which data relating to the performance of second pillar pension schemes are collated, compared and reported. This is done with regard to the performance of mandatory private second pillar pension funds in Eastern Europe. By critically examining data published in a number of World Bank studies, and through the identification of data problems and irregularities, the article argues that a much more elaborate and transparent approach to the collation, comparative analysis and reporting of data is needed. Required is the establishment of a consensus regarding what should represent a robust basis for making credible policy recommendations, not least with regard to pension re‐reforms in the countries of Eastern Europe and elsewhere. In the absence of such a consensus, unresolved data problems and irregularities may potentially continue to influence the formulation of incomplete national policy conclusions regarding the performance of second pillar pension funds and, in turn, the ability of policy‐makers to evaluate appropriately the need for, and assess the feasibility of implementing in a sustainable manner, pension re‐reform.     

From pension funds to piggy banks: (Perverse) consequences of the Stability and Growth Pact since the crisis

As part of their strategy for economic and monetary union, European governments committed themselves to fiscal discipline – particularly by placing limits on annual deficits and on public debt. Subsequently, and as they sought to respond to the “current crisis”, they embraced the view that only if public finances were kept under control would sustainable recovery be possible. Rules of fiscal governance were strengthened. To help them meet these rules, the governments of many member States of the European Union made changes to their pension systems or to funds they had established specifically to pay the costs of population ageing. The intention was not to cut retirement benefits or to improve the efficiency of the relevant pension schemes and institutions. Rather, it was to free up resources immediately. Funded pension schemes and pension funds were treated like “piggy banks” that were raided when times became hard. Moreover, the policies pursued succeeded in meeting their objectives only because the system of national accounts according to which outcomes are judged does not recognize the way in which most of the fiscal gains are matched by future fiscal liabilities.