Estimation of context in random fields

When considering the problem of the classification of satellite data, several authors have shown the superiority of the contextual method over the blind (pixel by pixel) method. Determining the discriminating functions which define the best contextual strategy (in the Bayesian sense) requires knowledge of the distribution of the restriction of the random field which models the picture, to the given context. We propose an estimator of this distribution and demonstrate its good asymptotic behaviour in very weak hypotheses.     

The Folk Theorem for Games with Private Almost‐Perfect Monitoring

We prove the folk theorem for discounted repeated games under private, almost‐perfect monitoring. Our result covers all finite, n‐player games that satisfy the usual full‐dimensionality condition. Mixed strategies are allowed in determining the individually rational payoffs. We assume no cheap‐talk communication between players and no public randomization device.     

Bayesian prediction with an asymmetric criterion in a nonparametric model of insurance risk

A median-unbiased estimator of the characteristic exponent of a symmetric stable distribution is constructed.     

A model of consumption-dependent temptation

The paper characterizes axiomatically a class of temptation-driven preferences. The key (but not the only) novelty of the paper is the idea that the alternative which tempts when an item x is consumed may not be the same as the alternative which tempts when another item y is consumed. For any single item to be ultimately consumed, the other items can be ranked by how much they tempt. An individual contemplates, as an alternative consumption, only the item that tempts most. The utility of a menu is then equal to the utility of the item that is consumed less a (psychological) cost of resisting temptation; this cost depends on both: the item to be consumed and the item that tempts. Unlike most of the existing literature, the axioms are imposed on deterministic menus, not on menus of lotteries.     

Knowing that you mimic me: the link between mimicry,awareness and liking

Mimicry pays off for a mimicker, and that mimickees are not aware of being influenced by mimicry. In this study, we investigated the link between mimicry, awareness and liking using a 2 (mimicry: yes/no) × 4 (awareness manipulation) experimental design. We found a main effect of mimicry (the confederate was liked more in the mimicry condition) and an interaction between mimicry and awareness. Awareness manipulation had a limited effect on the association between mimicry and liking. Providing participants with little or no information about mimicry (information not including any remarks about its consequences) had an effect on the association between mimicry and liking. However, when participants were informed about the interpersonal consequences of mimicry, mimicry did not influence liking.     

Rank correlation estimators and their limiting distributions

We examine a new rank correlation estimator, recently proposed by Bobrowski (Ranked modelling of risk on the basis of survival data. ICSMRA, Lisbon, 2007). It is obtained by minimization of a convex piece-wise linear criterion function. The main advantage of this estimator is the fact that it can be effectively computed by algorithms related to linear programming. We prove basic asymptotic theorems about the estimator: consistency and asymptotic normality.     

Effects of Government Support of Nonprofit Institutions on Aggregate Private Philanthropy: Evidence from 40 Countries

This paper examines the effects of aggregate government payments to nonprofit organizations on aggregate private philanthropy. Four behavioral models of private philanthropic giving are proposed to formulate four hypotheses about those effects: no net effect (null hypothesis), crowding in (positive effect), crowding out (negative effect), and “philanthropic flight” or displacement (negative effect across different subsectors). These hypotheses were tested against the evidence from 40 countries collected as a part of a larger research project aimed to document the scale and finances of the nonprofit sector. The data show that, on the balance, government payments to nonprofit institutions (NPIs) have a positive effect on aggregate philanthropic donations to nonprofits, as stipulated by the crowding in hypothesis, but a field level analysis revealed evidence of “philanthropic flight” or displacement from “service” to “expressive” activities by government payments to “service” NPIs. Due to the limitations of the data, these results indicate empirical plausibility of the hypothesized effects rather than their incidence. The findings demonstrate the complexity of the relationship between government funding and philanthropic donations to nonprofits, which depends on the goals of the actors (donors and recipients) and institutional settings mediating the transaction costs of difference sources of nonprofit support.     

On exact computation of minimum sample size for restricted estimation of a binomial parameter

The problem of determining minimum sample size for the estimation of a binomial parameter with prescribed margin of error and confidence level is considered. It is assumed that available auxiliary information allows to restrict the parameter space to some interval whose left boundary is above zero. A range-preserving estimator resulting from the conditional maximization of the likelihood function is considered. A method for exact computation of minimum sample size controlling for the relative error is proposed. Several tables of minimum sample sizes for typical situations are also presented. The range-preserving estimator achieves the same precision and confidence level as the unrestricted maximum likelihood estimator but with a smaller sample.     

Estimation of finite population kurtosis under two-phase sampling for nonresponse

In this paper an estimator of finite population kurtosis computed under the two-phase sampling for nonresponse is proposed. The formulas characterizing its asymptotic properties are derived using Taylor linearization technique for the general situation of arbitrary sampling designs in both phases and stochastic nonresponse represented by arbitrary response distribution. An important special case of simple random sampling without replacement and deterministic nonresponse is also considered.