Hurricane Katrina struck New Orleans on the 29th of August 2005 and displaced virtually the entire population of the city. Soon after, observers predicted the city would become whiter and wealthier as a result of selective return migration, although challenges related to sampling and data collection in a post-disaster environment have hampered evaluation of these hypotheses. In this article, we investigate return to the city by displaced residents over a period of approximately 14 months following the storm, describing overall return rates and examining differences in return rates by race and socioeconomic status. We use unique data from a representative sample of pre-Katrina New Orleans residents collected in the Displaced New Orleans Residents Pilot Survey. We find that black residents returned to the city at a much slower pace than white residents even after controlling for socioeconomic status and demographic characteristics. However, the racial disparity disappears after controlling for housing damage. We conclude that blacks tended to live in areas that experienced greater flooding and hence suffered more severe housing damage which, in turn, led to their delayed return to the city. The full-scale survey of displaced residents being fielded in 2009–2010 will show whether the repopulation of the city was selective over a longer period.

We present theoretical arguments and empirical research to suggest that the principal mechanisms of cumulative causation do not function in large urban settings. Using data from the Mexican Migration Project, we found evidence of cumulative causation in small cities, rural towns and villages, but not in large urban areas. With event-history models, we found little positive effect of community-level social capital and a strong deterrent effect of urban labor markets on the likelihood of first and later U.S. trips for residents of urban areas in Mexico, suggesting that the social process of migration from urban areas is distinct from that in the more widely studied rural migrant-sending communities of Mexico.

Anthropogenic sea-level rise (SLR) is predicted to impact, and, in many cases, displace, a large proportion of the population via inundation and heightened SLR-related hazards. With the global coastal population projected to surpass one billion people this century, SLR might be among the most costly and permanent future consequences of climate change. In this Review, we synthesize the rapidly expanding knowledge of human mobility and migration responses to SLR, providing a coherent roadmap for future SLR research and associated policy. While it is often assumed that direct inundation forces a migration, we discuss how mobility responses are instead driven by a diversity of socioeconomic and demographic factors, which, in some cases, do not result in a migration response. We link SLR hazards with potential mechanisms of migration and the associated governmental or institutional policies that operate as obstacles or facilitators for that migration. Specific examples from the USA, Bangladesh and atoll island nations are used to contextualize these concepts. However, further research is needed on the fundamental mechanisms underlying SLR migration, tipping points, thresholds and feedbacks, risk perception and migration to fully understand migration responses to SLR.

Natives' attitudes toward immigrants and immigration policy are important factors in the context of reception of immigrants since they contribute to a warm or chilly welcome, which potentially shapes immigrant and ethnic identities and inter-group relations. Public opinion polls show a recent “warming” of Americans' traditional ambivalence about immigration. Empirical research on attitudes toward immigrants and racial groups formed by recent waves of immigrants resonate with the dynamic nature of Blumer's (1958) theory of prejudice as a sense of relative group position. To better understand this dynamism, research that intentionally contrasts study sites on conflict and contact conditions and the presence of absence of symbolic politics, as well as research with different native-born racial and ethnic groups, would reveal a broader range of natives' attitude formation processes and the role they play in immigrant reception.