Does Residential Context Matter? Neighborhood Migrant Concentration and Citizenship Acquisition in the Netherlands

Existing studies analyzing the relation between immigrants' residential environment and their propensity to naturalize produce contradictory findings. These results are difficult to interpret, as studies typically do not measure residential characteristics at a sufficiently fine-grained scale to test hypotheses about social networks and naturalization, do not model the data's multi-level structure appropriately, and do not account for selection into the residential environment. To address these shortcomings, this article draws on longitudinal micro-data from administrative registers at the neighborhood level in the Netherlands (approximately 1300 residents per neighborhood). We employ a stratified Cox proportional hazard model with shared frailty and inverse probability of treatment weighting to reduce bias due to self-selection into neighborhoods and draw on proxies of social networks in such areas. Our analyses provide support for the 'migrant enclosure hypothesis,' as we find that greater migrant concentration in the neighborhood is associated with lower naturalization rates and largely driven by the density of migrant social networks in those residential areas. In the Dutch context, this negative effect of migrant enclosure is especially prevalent among the large, long-settled migrant communities from Morocco and Turkey. We also find support for the 'naturalization diffusion hypothesis' and observe that the negative naturalization effect of residing in neighborhoods with higher levels of migrant concentration is offset by the presence of immigrants who have completed the naturalization procedure. Together, these findings reveal a nuanced picture that contrasts with de-contextualized cost-benefit theories of immigrant naturalization and highlights the relevance of the local context of immigrant settlement.