Are we just friends? Immigrant integration into high- and low-cost social networks:

We argue that the degree of ethnic segregation in multiplex social networks depends on the cost of ties in different network dimensions, which is motivated by the distinction between low- and high-cost situations in rational choice theory. We assume that ethnic boundaries become more important, the closer a relationship is and the higher the costs of a social tie are. By estimating Exponential Random Graph ( p* ) models for complete social networks in school classes of 1228 students and 19,764 dyads, we test this assumption. We analyse the degree of ethnic segregation not only in friendship networks, but also in ‘more costly’ networks such as leisure time spent together, visits to one another’s home and contact between children’s parents. In line with our expectation it will be shown that the degree of segregation increases the higher the costs of ties in social networks are.