Multistate life table with duration dependence: An application to Hungarian female marital history

Multistate life table methods have been recognized as an excellent tool in the analysis of many types of transitions. Yet demographers have never been completely satisfied with the Markovian assumption and have stressed the importance of population heterogeneity. In marital status analysis, for example, the time spent in the current status is thought to be of first importance in determining transitions, but computational problems linked to the introduction of duration prevented any estimation of the bias in life table calculations arising from its omission. Building on recent developments in multistate demography, and using data from the 1984 Hungarian microcensus, this paper analyzes the impact that the introduction of duration-specific transitions has on the results of a multistate life table analysis of marital dissolution. The results show that the inclusion of duration has its greatest impact on the distribution of the stationary population between ages 25 and 35.Les tables de survie multi-états ont été reconnues comme un très bon instrument pour l'analyse de nombreux types de transitions. Cependant les démographes n'ont jamais été complètement satisfaits des hypothèses markoviennes et ont insisté sur l'importance de l'hétérogénéité des populations étudiées. Dans l'analyse par état matrimonial, par exemple, le temps passé dans l'état étudié est considéré comme de première importance dans la détermination des transitions. Cependant des problèmes de calcul liés à l'introduction de cette durée avaient empêché toute estimation des biais venant de son omission dans le calcul des tables de survie. Utilisant des développements récents en démographie multi-état et utilisant des données du micro-recensement hongrois de 1984, cet article analyse l'impact que l'introduction de transitions dépendant de la durée, a sur une analyse multi-état des dissolutions de mariages. Les résultats montrent que l'inclusion de la durée a un effet maximum sur la distribution de la population stationnaire, entre les âges de 25 at 35 ans.     

Sharing beliefs and the absence of betting in the Choquet expected utility model

Choquet expected utility maximizers tend to behave in a more “cautious” way than Bayesian agents, i. e. expected utility maximizers. We illustrate this phenomenon in the particular case of betting behavior. Specifically, consider agents who are Choquet expected utility maximizers. Then, if the economy is large, Pareto optimal allocations provide full insurance if and only if the agents share at least on prior, i. e., if the intersection of the core of the capacities representing their beliefs is non empty. In the expected utility case, this is true only if they have a common prior. Received: July 2000; revised version: May 2001     

Social Protection: Values to be Defended!

Social protection is a part of human rights. I therefore believe it is important to react to the many reproaches levelled at it, which are undermining its legitimacy. This involves defending social protection, first and foremost in the name of its mission, its fundamental objectives and, consequently, the values upon which it is founded. After briefly reviewing the content of these values, I emphasize the fact that they should be promoted and cultivated at least as much as the economic values that are dominant in the world today.     

Small-sample results for maximum-likelihood estimation in branching processes

In this article, small sample properties of the maximum-likelihood estimator (m.l.e.) for the offspring distribution (pk) and its mean m are considered in the context of the simple branching process. A representation theorem is given for the m.l.e. of (Pk) from which the m.l.e. of m is obtained. The case where p0 + p1 + p2 = 1 is studied in detail: numerical results are given for the exact bias of these estimators as a function of the age of the process; a curve fitting analysis expresses the bias of m? as a function of the mean and the variance of the offspring distribution and finally an “approximate m.l.e.” for (pk) is given.     

Estimators of shift based on statistics of the Kolmogorov-Smirnov type

This paper is concerned with the estimation of a shift parameter δ_o, based on some nonnegative functional Hg₁ of the pair (D^δ_N(x), f?^δ_N(x)), where D^δ_N(x) = K_N/b {F_2,n(x)—F_1,m (x + δ)}, +^δ_N(x) = {mF_1,m (x + δ) + nF_2,n(x)}/N, where F_1,m and F_2,n are the empirical distribution functions of two independent random samples (N = m + n), and where K²_N = mn/N. First an estimator δ_N, is defined as a value of δ minimizing a functional H of the type of H₁. A second estimator δ¹_N is also defined which is a linearized version of the first. Finite and asymptotic properties of these estimators are considered. It is also shown that most well-known test statistics of the Kolmogorov-Smirnov type are particular cases of such functionals H₁. The asymptotic distribution and the asymptotic efficiency of some estimators are given.     

Lorenz non-consistent welfare and inequality measurement

Typical welfare and inequality measures are required to be Lorenz consistent which guarantees that inequality decreases and welfare increases as a result of a progressive transfer. We explore the implications for welfare and inequality measurement of substituting the weaker absolute differentials and deprivation quasi-orderings for the Lorenz quasi-ordering. Restricting attention to distributions of equal means, we show that the utilitarian model - the so-called expected utility model in the theory of risk - does not permit one to make a distinction between the views embedded in the differentials, deprivation and Lorenz quasi-orderings. In contrast it is possible within the dual model of M. Yaari (Econometrica 55 (1987), 99–115) to derive the restrictions to be placed on the weighting function which guarantee that the corresponding welfare orderings are consistent with the differentials and deprivation quasi-orderings respectively. Finally we drop the equal mean condition and indicate the implications of our approach for the absolute ethical inequality indices.     

Optimal Ordering Policies for Stochastic Inventory Problems with Observed Information Delays

Information delays exist in an inventory system when it takes time to collect, process, validate, and transmit inventory/demand data. A general framework is developed in this paper to describe information flows in an inventory system with information delays. We characterize the sufficient statistics for making optimal decisions. When the ordering cost is linear, the optimality of a state‐dependent base‐stock policy is established even when information flows are allowed to cross over time. Additional insights into the problem are obtained via a comparison between our models and the models with stochastic order lead times. We also show that inventory can substitute for information and vice versa.