Reliability,Population Classification and Weighting in Multidimensional Poverty Measurement: A Monte Carlo Study

Social Indicators Research - In poverty measurement, differential weighting aims to take into account the unequal importance of the diverse dimensions and aspects of poverty and to add valuable...     

Inflation projections for monetary policy decision making

Many central banks set inflation targets over the medium term and inflation projections are a key input for monetary policy decision making. In this paper, we present the procedures used by the Spanish Central Bank staff to project consumer price inflation. We also provide some illustrations of their policy uses, such as fan charts, deflation probabilities and the monitoring of inflation targets.     

The End of “Lowest‐Low” Fertility?

Total fertility rates fell to previously unseen levels in a large number of countries beginning in the early 1990s. The persistence of TFRs below 1.3 raised the possibility of rapid population aging and decline. We discuss the recent widespread turnaround in so‐called lowest‐low‐fertility countries in Europe and East Asia. The number of countries with TFRs below 1.3 fell from 21 in 2003 to five in 2008. Moreover, the upturn in the TFR was not confined to lowest‐fertility countries, but affected the whole developed world. We explore the demographic explanations for the recent rise in TFRs stemming from fertility timing effects as well as economic, policy, and social factors. Although the current economic downturn may suppress TFRs in the short run, we conclude that formerly lowest‐low‐fertility countries will continue to see increases in fertility as the transitory effects of shifts to later childbearing become less important.     

New lower bounds for the second variable Zagreb index

The aim of this paper is to obtain new sharp inequalities for a large family of topological indices, including the second variable Zagreb index \(M_2^{\alpha }\), and to characterize the set of extremal graphs with respect to them. Our main results provide lower bounds on this family of topological indices involving just the minimum and the maximum degree of the graph. These inequalities are new even for the Randi?, the second Zagreb and the modified Zagreb indices.     

New bounds for locally irregular chromatic index of bipartite and subcubic graphs

A graph is locally irregular if the neighbors of every vertex v have degrees distinct from the degree of v. A locally irregular edge-coloring of a graph G is an (improper) edge-coloring such that the graph induced on the edges of any color class is locally irregular. It is conjectured that three colors suffice for a locally irregular edge-coloring. In the paper, we develop a method using which we prove four colors are enough for a locally irregular edge-coloring of any subcubic graph admiting such a coloring. We believe that our method can be further extended to prove the tight bound of three colors for such graphs. Furthermore, using a combination of existing results, we present an improvement of the bounds for bipartite graphs and general graphs, setting the best upper bounds to 7 and 220, respectively.     

THE INFORMATION TECHNOLOGY REVOLUTION AND THE UNSECURED CREDIT MARKET

The information technology (IT) revolution coincided with the transformation of the U.S. unsecured credit market. Households' borrowing increased rapidly and there was an even faster increase in bankruptcy filings. A risk of default model with asymmetric information and costly screening is introduced to study this period. When information costs are high, the design of contracts under private information prevents some households from borrowing with a risk of default. As information costs drop, households borrow more and bankruptcy filings increase. Quantitative exercises suggest that the IT revolution may have played an important role in the transformation of the unsecured credit market. (JEL E43, E44, G33)     

Les transferts de fonds et leur effet sur les indicateurs du marché du travail: illustration par le cas mexicain

L'effet des envois de fonds sur les indicateurs du marché du travail est abondamment traité dans la littérature, à partir de microdonnées en général. Les macrodonnées, plus rarement utilisées, posent un problème d'endogénéité lié aux corrélations possibles de la variable relative aux transferts. Dans cette analyse, fondée sur des données de panel relatives au Mexique, les auteurs cherchent à contourner le problème en utilisant un estimateur GMM en système. Ils montrent que les envois de fonds élèvent les taux d'activité tout en réduisant le nombre des heures travaillées, la fréquence de l'emploi «critique» (c'est‐à‐dire de mauvaise qualité) et la durée des épisodes de chômage.     

A simple two-stage design for quantitative responses with application to a study in diabetic neuropathic pain

Two-stage designs offer substantial advantages for early phase II studies. The interim analysis following the first stage allows the study to be stopped for futility, or more positively, it might lead to early progression to the trials needed for late phase II and phase III. If the study is to continue to its second stage, then there is an opportunity for a revision of the total sample size. Two-stage designs have been implemented widely in oncology studies in which there is a single treatment arm and patient responses are binary. In this paper the case of two-arm comparative studies in which responses are quantitative is considered. This setting is common in therapeutic areas other than oncology. It will be assumed that observations are normally distributed, but that there is some doubt concerning their standard deviation, motivating the need for sample size review. The work reported has been motivated by a study in diabetic neuropathic pain, and the development of the design for that trial is described in detail.     

Bayesian robustness of the compound Poisson distribution under bidimensional prior: an application to the collective risk model

The distribution of the aggregate claims in one year plays an important role in Actuarial Statistics for computing, for example, insurance premiums when both the number and size of the claims must be implemented into the model. When the number of claims follows a Poisson distribution the aggregated distribution is called the compound Poisson distribution. In this article we assume that the claim size follows an exponential distribution and later we make an extensive study of this model by assuming a bidimensional prior distribution for the parameters of the Poisson and exponential distribution with marginal gamma. This study carries us to obtain expressions for net premiums, marginal and posterior distributions in terms of some well-known special functions used in statistics. Later, a Bayesian robustness study of this model is made. Bayesian robustness on bidimensional models was deeply treated in the 1990s, producing numerous results, but few applications dealing with this problem can be found in the literature.