Love,necessity and opportunity: Changing patterns of marital age homogamy in the Netherlands, 1850–1993

Abstract. This article examines long-term trends in the pattern of age homogamy among first marriages, using vital registration data on all first marriages contracted between 1850 and 1993 in the Netherlands. After discussing the main mechanisms that could account for trends in age differences, we show that age differences between spouses narrowed considerably between 1850 and 1970. After 1970 the trend becomes less clear-cut.     

Log-density Deconvolution by Wavelet Thresholding

Abstract.  This paper proposes a new wavelet-based method for deconvolving a density. The estimator combines the ideas of non-linear wavelet thresholding with periodized Meyer wavelets and estimation by information projection. It is guaranteed to be in the class of density functions, in particular it is positive everywhere by construction. The asymptotic optimality of the estimator is established in terms of the rate of convergence of the Kullback–Leibler discrepancy over Besov classes. Finite sample properties are investigated in detail, and show the excellent empirical performance of the estimator, compared with other recently introduced estimators.     

LEADERSHIP BY EXAMPLE IN THE WEAK‐LINK GAME

We investigate the effects of leadership in a four‐player weak‐link game. A weak‐link game is a coordination game with multiple Pareto‐ranked Nash equilibria. Because the more efficient equilibria involve a degree of strategic uncertainty groups typically find it difficult to coordinate on more efficient equilibria. We wanted to see whether leadership by example, in the form of one player acting publicly before the rest of the group, could help groups do better. Our results suggest that leadership can increase efficiency but is far from being a guarantee of success. Specifically, in a significant number of groups we observed successful leadership and increased efficiency, but in most groups efficiency was low despite the efforts of leaders. We did not find any difference between voluntary leaders and leaders that are randomly assigned. (JEL C72, H41)     

Erratum

In our article entitled "The Social Bases of Environmental Concern:A Review of Hypotheses, Explanations and Empirical Evidence"(POQ 44:181–97), two rows of correlations were reversedin Table 1. Under the study by Van Liere and Dunlap, 1978, figuresfor the environmental funding scale appear where figures forthe environmental regulations scale should be, and vice versa.We regret the error and hope it has not caused undue confusionfor anyone using these data.     

Disagreement Loop and Path Creation/Annihilation Algorithms for Binary Planar Markov Fields with Applications to Image Segmentation

Abstract. We introduce a class of Gibbs–Markov random fields built on regular tessellations that can be understood as discrete counterparts of Arak–Surgailis polygonal fields. We focus first on consistent polygonal fields, for which we show consistency, Markovianity and solvability by means of dynamic representations. Next, we develop disagreement loop as well as path creation and annihilation dynamics for their general Gibbsian modifications, which cover most lattice‐based Gibbs–Markov random fields subject to certain mild conditions. Applications to foreground–background image segmentation problems are discussed.     

The multiplicity of citizenship: transnational and local practices and identifications of middle‐class migrants

In this article we focus on local and transnational forms of active citizenship, understood as the sum of all political practices and processes of identification. Our study, conducted among middle‐class immigrants in Rotterdam, the Netherlands, indicates that the importance of active transnational citizenship should not be overstated. Among these immigrants, political practices are primarily focused on the local level; political practices directed to the home country appear to be quite rare. However, although transnational activities in the public sphere are rather exceptional, many immigrants do participate in homeland‐directed activities in the private sphere. If we look at processes of identification, we see that a majority of the middle‐class immigrants have a strong local identity. Many of them combine this local identification with feelings of belonging to people in their home country.