On the determination of sizes of markets

The number of specialized dealers is of interest to market research institutes. They need those market sizes to project sample results to the whole population of shops. A basis to get to know the size of such a population is given by address registers. These registers contain also dead addresses and they are incorrect as they do not contain all addresses of existing shops. We present an approach to deal with these two kinds of errors and derive an estimator with negligible bias.     

Towards a Political Theory of Migrant Transnationalism

Political transnationalism covers a wide range of phenomena and can be studied using a variety of approaches. In migration research the focus is mostly on migrants' networks and activities that involve them in politics oriented towards their country of origin. The article argues for a wider conception of political transnationalism from a political theory perspective. It proposes a terminological distinction between international, multinational, supranational and transnational relations and phenomena. What is specific about migrant transnationalism is that it creates overlapping memberships between territorially separated and independent polities. In this understanding, political transnationalism is not only about a narrowly conceived set of activities through which migrants become involved in the domestic politics of their home countries; it also affects collective identities and conceptions of citizenship among the native populations in both receiving and sending societies. Within this general framework the article suggests a set of hypotheses for an explanatory and normative analysis of sending country relations to their emigrants, a task that has hitherto been neglected in political theory.     

Optimal Designs for Additive Linear Models

In additive linearr models optimal designs can be constructed as a product of those marginal designs which have certain optimality properties in the corresponding single-factor models. In particular, these results are obtained for the reduced parameter vector without constant term and for the parameters associated with single factors.     

Optimal design for discrete choice experiments

In this paper we derive locally optimal designs for discrete choice experiments. As in Kanninen (2002) we consider a multinomial logistic model, which contains various qualitative attributes as well as a quantitative one, which may range over a sufficiently large interval. The derived optimal designs improve upon those given in the literature, but have the feature that every choice set contains alternatives, which coincide in all but the quantitative attributes. The multinomial logistic model will then lead to a response behavior, which is apparently unrealistic.     

An Empirical Analysis of the Decision to Train Apprentices

Abstract. It is a widely held belief that apprenticeship training represents a net investment for training firms, the cost of which needs to be recouped after the training period. A new firm‐level data set for Switzerland reveals large variation in net costs across firms and, remarkably, negative net costs for 60 per cent of all firms. We use these data to estimate the effect of net costs on the number of apprentices hired by a firm. The results show that the costs have a significant impact on the training decision but no significant influence on the number of apprentices, once the firm has decided to train. For policy purposes, these results indicate that subsidies for firms that already train apprentices would not boost the number of available training places.     

Block‐threshold‐adapted Estimators via a Maxiset Approach

We study the maxiset performance of a large collection of block thresholding wavelet estimators, namely the horizontal block thresholding family. We provide sufficient conditions on the choices of rates and threshold values to ensure that the involved adaptive estimators obtain large maxisets. Moreover, we prove that any estimator of such a family reconstructs the Besov balls with a near‐minimax optimal rate that can be faster than the one of any separable thresholding estimator. Then, we identify, in particular cases, the best estimator of such a family, that is, the one associated with the largest maxiset. As a particularity of this paper, we propose a refined approach that models method‐dependent threshold values. By a series of simulation studies, we confirm the good performance of the best estimator by comparing it with the other members of its family.