Detecting communities in complex networks accurately is a prime challenge, preceding further
analyses of network characteristics and dynamics. Until now, community detection took into account
only positively valued links, while many actual networks also feature negative links. We extend an
existing (spin glass) approach to incorporate negative links as well, resulting in a method similar to
the clustering of signed graphs, but more accurate and more general. To illustrate our method, we
applied it to a network of international alliances and disputes. Using data from 1993{2001, it turns
out that the world can be divided into six power blocs similar to Huntington’s civilizations, with
some notable exceptions.

This study contributes to earlier studies aimed at the question of whether the welfare state
crowds out social capital or not by examining to what extent the welfare state affects the
value of social capital. This article investigates the effects of three sources of social capital
on occupational prestige and tests whether these effects are moderated by welfare state
effort in terms of social spending. Multi-level analyses based on European Social Survey
(ESS) 2002/03 and International Monetary Fund (IMF) data, including 39,299 people from
24 European countries, provides evidence that welfare state effort decreases the value
of social capital.