We analyze the illicit drug usage by inhabitants and visitors of European cities. Our statistical analyses are by means of linear mixed models. The data on illicit drug usage of cocaine, ecstasy, amphetamines, methamphetamines, and cannabis are collected through wastewater samples from the inlet...

We study the impact of early cannabis use on the school to work transition of young men. Our empirical approach accounts for common unobserved confounders that jointly affect selection into cannabis use and the transition from school to work using a multivariate mixed proportional hazard...

In this paper we test the celebrated `Strength of weak ties' theory of Granovetter (1973). We test two hypotheses on the network structure in a data set of collaborating economists. While we find support for the hypothesis of transitivity of strong ties, we reject the hypothesis that weak ties...

Previous research on firm performance does not adequately account for the interrelatedness of a firm's professional connections, political ties, and family business-group affiliation. Many widely-cited findings may therefore be subject to confounding bias. To address this problem, we adopt a...

Purpose: This paper addresses the nature, formalization, and neural bases of (affective) social ties anddiscusses the relevance of ties for health economics. A social tie is defined as an affectiveweight attached by an individual to the well-being of another individual...

This paper evaluates the strength of social and economic forces that affect the pressure to emigrate 'out of Africa' for four distinctly different African countries (Morocco, Egypt, Senegal and Ghana). In general, great expectations about attaining a higher living standard and expected low job...

I study a one-way flow connections model in which players are heterogeneous with respect to values and the costs of establishing a link. I first show that values and costs asymmetries are crucial in determining the level of connectedness of a network. Interestingly, unconnected equilibria are...