A note on asymptotic distributions in directed exponential random graph models with bi-degree sequences

The asymptotic normality of a fixed number of the maximum likelihood estimators (MLEs) in the directed exponential random graph models with an increasing bi-degree sequence has been established recently. In this article, we further derive a central limit theorem for a linear combination of all the MLEs with an increasing dimension. Simulation studies are provided to illustrate the asymptotic results.     

Testing for Threshold Diffusion

The threshold diffusion model assumes a piecewise linear drift term and a piecewise smooth diffusion term, which constitutes a rich model for analyzing nonlinear continuous-time processes. We consider the problem of testing for threshold nonlinearity in the drift term. We do this by developing a quasi-likelihood test derived under the working assumption of a constant diffusion term, which circumvents the problem of generally unknown functional form for the diffusion term. The test is first developed for testing for one threshold at which the drift term breaks into two linear functions. We show that under some mild regularity conditions, the asymptotic null distribution of the proposed test statistic is given by the distribution of certain functional of some centered Gaussian process. We develop a computationally efficient method for calibrating the p-value of the test statistic by bootstrapping its asymptotic null distribution. The local power function is also derived, which establishes the consistency of the proposed test. The test is then extended to testing for multiple thresholds. We demonstrate the efficacy of the proposed test by simulations. Using the proposed test, we examine the evidence of nonlinearity in the term structure of a long time series of U.S. interest rates.     

The ABCs of nonfinancial defined contribution (NDC) schemes

Nonfinancial defined contribution (NDC) pension schemes have been successfully implemented since the mid‐1990s in a number of European countries such as Italy, Latvia, Norway, Poland and Sweden. The NDC approach features the lifelong contribution–benefit link of a financial defined contribution (FDC) personal account scheme, but is based on the pay‐as‐you‐go (PAYG) format. At its start out, the PAYG commitments of the preceding defined benefit (DB) system are converted into individual personal accounts, allowing for a smooth transition from the DB to the DC format, while avoiding the very high transition costs inherent in a move from a traditional PAYG DB scheme to a fully funded FDC scheme. The NDC approach implemented by the rule book is able to manage the economic and demographic risks inherent to a pension scheme and, by design, creates financial sustainability. As in any pension scheme, the linchpin between financial stability and adequacy is the retirement age; in the NDC approach the individual retirement age above the minimum age is by design self‐selected and by incentives should increase the effective retirement age in line with population ageing. As a systemic reform approach NDC has become a strong competitor to piecemeal parametric reforms of traditional nonfinancial DB (NDB) schemes. While frequent, these reforms are far from transparent and usually too timid and too late to create financial sustainability while providing adequate pensions for the average contributor. This article offers a largely non‐technical introduction to NDC schemes, their basic elements and advantages over NDB schemes, the key technical frontiers of the approach, and the experiences of NDC countries.     

La dimension sociale du commerce international à la lumière du pluralisme de l'Organe d'appel de l'OMC

Pour certains juristes du travail, les règles de l'OMC pourraient empêcher les États de sanctionner comme ils l'entendent les atteintes aux normes et droits relatifs au travail protégés par le droit national ou international, sur leur sol ou ailleurs. Cependant, dans sa jurisprudence, l'Organe d'appel de l'organisation a admis un certain pluralisme des règles, protégeant ainsi l'autonomie des État en matière réglementaire. Cette interprétation élargit également le champ des exceptions autorisées, et elle atténue la portée dérégulatrice de certaines dispositions du droit de l'OMC. De nombreuses mesures de protection des travailleurs pourraient donc devenir acceptables et compatibles avec les règles du droit commercial international.     

Les dépenses de sécurité sociale vont-elles de pair avec de meilleurs résultats des entreprises? Étude de cas sur les PME indonésiennes

Le lien entre protection sociale et résultats des entreprises est abondamment étudié, mais on manque d'informations sur la situation des petites et moyennes entreprises des économies en développement. L'auteure examine ce lien à partir de données de recensement indonésiennes portant sur la période 2010-2014. Elle constate que, lorsque les dépenses de sécurité sociale augmentent de 10 pour cent, le chiffre d'affaires par travailleur progresse de 2 pour cent. De même, l'extension de la couverture sociale n'entraîne pas de baisse du bénéfice, ce qui laisse penser que les entreprises pourraient avoir intérêt à investir dans la sécurité sociale de leur personnel.     

Payment of Universal Credit for couples in the UK: Challenges for reform from a gender perspective

Universal Credit has been rolled out gradually in the United Kingdom since 2013 as one integrated means-tested benefit replacing six different transfers with a single monthly payment. Previously, these benefits were awarded for distinct purposes and, for couples who claimed them, were potentially payable to different partners. Concerns about Universal Credit’s single payment include the opportunities it may create for facilitating domestic abuse, the fostering of more unequal power relations within couples, the reduction of financial autonomy for individuals, and the de-labelling of benefit payments. This article explores debates about the prospects for individual payments to partners in couples of Universal Credit as a jointly assessed integrated means-tested benefit, including different approaches emerging from the United Kingdom’s devolved governments (mainly Scotland and Northern Ireland). Whilst payment to each partner is likely to be more feasible where there are separate rather than integrated means-tested benefits, it concludes that genuine financial autonomy for partners in couples is best pursued via individually based non-means-tested benefits.     

Social protection and revenue collection: How they can jointly contribute to strengthening social cohesion

Social protection and revenue collection are often regarded as potential drivers of social cohesion. The article joins this debate, providing three main contributions. First, we carefully discuss the concept of social cohesion and endorse one specific definition. Second, we propose using the concept of the “fiscal contract” as the key theoretical lens to understand the often neglected potential joint effects of social protection and revenue collection policies on social cohesion. Third, we illustrate three main mechanisms through which these policies can have positive or negative impacts on the different components of social cohesion and highlight the relevance of these for policy-makers deliberations.     

A geometric process warranty model using a combination policy

This paper proposes a geometric process warranty model. Assume that a combination policy (W, T) is applied after selling a product, so that a free warranty is offered in [0, W), followed by a pro-rata warranty in [W, T). Assume further the successive operating times (repair times) of the product form a decreasing (increasing) geometric process. The average cost rate of the product to the manufacturer and a consumer can be derived respectively. For exponential distribution case, the explicit formulas of the average cost rate are obtained, and an finite algorithm for determination of an optimal combination policy is suggested.     

BSDEs driven by time-changed Lévy noises with non-Lipschitz generators

This paper deals with a class of backward stochastic differential equations (BSDEs for short) driven by time-changed Lévy noises. The existence and uniqueness of L^p(p ? 2) solutions for this kind of BSDEs with non-Lipschitz generators are obtained, which extend the corresponding results of Di Nunno and Sjursen (2014) [Stochastic Process. Appl. 124(4):1679-1709]. Furthermore, representation theorem for generators as well as converse comparison theorem for this kind of BSDEs are also studied.     

TIC et gains de productivité en Afrique subsaharienne

Les auteurs examinent les effets des TIC sur la productivité à partir d'un échantillon de 43 pays d'Afrique subsaharienne. Ils concluent que le développement des téléphonies fixe et mobile stimule la croissance de la productivité dans un processus à rendements croissants, confirmant l'existence d'un effet de réseau. Ainsi, la multiplication par deux du taux de pénétration des téléphonies fixe et mobile augmente les gains de productivité de 0,12 à 0,15 et 0,05 pour cent environ, respectivement. En outre, dans la région, l'accès facilité aux services bancaires et financiers serait l'un des vecteurs de l'effet de la téléphonie mobile sur la productivité.