Clique Networks and the “Clique Effect” Among Undocumented Migrants from Mexico to the United States

Recent work has shown that processes of cumulative causation, which derive from the accumulation of social capital within specific places, occurs not only in small villages but in medium-sized urban communities among both documented and undocumented migrants (Fussell and Massey 2004); and rather strong social capital effects have also been documented in urban settings among undocumented Mexican migrants (Flores et al. 2004). These findings are puzzling given that sociological theory suggests that social solidarity weakens with urbanization and industrialization (Durkheim [1933] 1984, Wirth 1938). Drawing upon qualitative and quantitative information I developed in the course of my fieldwork, I offer evidence in support of my theoretical argument that urban-based migrant networks are weak and mostly effective for helping people get to the United States. Once in the country, however, these networks prove fragile and urban migrants therefore gravitate to already- established rural-based