In the same spirit as Tsybakov [2003], we define the optimality of an aggregation procedure in the problem of classification. Using an aggregate with exponential weights, we obtain an optimal rate of convex aggregation for the hinge risk under the margin assumption. Moreover we obtain an optimal rate of model selection aggregation under the margin assumption for the excess Bayes risk. AMS 1991 ...

organizations need to evaluate project proposals and select the ones that are the most effective in reaching the strategic goals by considering sustainability issue. in order to enhance the effectiveness and the efficiency of project oriented organizations, in this paper a new multi-objective decision making (modm) approach of sustainable project portfolio selection is proposed which applies in...

A large empirical literature found that the correlation between insurance purchase and ex post realization of risk is often statistically insignificant or negative. This is inconsistent with the predictions from the classic models of insurance a la Akerlof (1970), Pauly (1974) and Rothschild and Stiglitz (1976) where consumers have one-dimensional heterogeneity in their risk types. It is sugges...

The Netherlands relies on risk equalization to compensate competing health insurers for predictable variation in individual medical expenses. Without accurate risk equalization insurers are confronted with incentives for risk selection. The goal of this study is to evaluate the improvement in predictive accuracy of the Dutch risk equalization model since its introduction in 1993. Based on indiv...

An excess of nonsynonymous over synonymous substitution at individual amino acid sites is an important indicator that positive selection has affected the evolution of a protein between the extant sequences under study and their most recent common ancestor. Several methods exist to detect the presence, and sometimes location, of positively selected sites in alignments of protein-coding sequences...

When females search for mates and their perceived risk of predation increases, they less often express preferences for males that use conspicuous courtship signals, relaxing sexual selection on production of these signals. Here, we report an apparent exception to this general pattern. Courting male fiddler crabs Uca beebei sometimes build pillars of mud at the openings to their burrows in which...

We analyze general model selection procedures using penalized empirical loss minimization under computational constraints. While classical model selection approaches do not consider computational aspects of performing model selection, we argue that any practical model selection procedure must not only trade off estimation and approximation error, but also the effects of the computational effort...

We test the predictions of different classic migration theories by using incentivized laboratory experiments to investigate how potential migrants decide between working in destinations. income maximization, migrant skill-selection, and multidestination choice as we vary costs, liquidity constraints, risk, social benefits, incomplete information. show standard maximization model with selection ...

This paper analyzes the optimal menu of contracts offered by a risk-neutral principal to risk-averse agent under moral hazard, adverse selection, and limited liability. We show that liability constraint causes pooling most efficient types. also find sufficient conditions which full is optimal, regardless agent's risk aversion or type distribution. Our model suggests offering single contract oft...