A Meta-Analysis of the Literature on Climate Change and Migration

in Journal of Demographic Economics (2021)

Recent surveys of the literature on climate change and migration emphasize the important diversity of outcomes and approaches of the empirical studies. In this pa- per, we conduct a meta-analysis in order ... [more ▼]

Recent surveys of the literature on climate change and migration emphasize the important diversity of outcomes and approaches of the empirical studies. In this pa- per, we conduct a meta-analysis in order to investigate the role of the methodological choices of these empirical studies in finding some particular results concerning the role of climatic factors as drivers of human mobility. We code 51 papers representative of the literature in terms of methodological approaches. This results in the coding of more than 85 variables capturing the methodology of the main dimensions of the analysis at the regression level. These dimensions include authors’ reputation, type of mobility, measures of mobility, type of data, context of the study, econometric methods and last but not least measures of the climatic factors. We look at the influence of these characteristics on the probability of finding any effect of climate change, of find- ing a displacement effect, of finding an increase in immobility and of finding evidence in favour of a direct versus an indirect effect. Our results highlight the role of some important methodological choices, such as the frequency of the data on mobility, the level of development, the measures of human mobility and of the climatic factors as well as the econometric methodology. [less ▲]

Dissecting Network externalities in International Migration

in Journal of Demographic Economics (2015), 81(4), 379-408

Migrant networks play an important role in explaining the size and structure of migration flows. They affect the private costs and benefits of migration (assimilation channel) and lower legal entry ... [more ▼]

Migrant networks play an important role in explaining the size and structure of migration flows. They affect the private costs and benefits of migration (assimilation channel) and lower legal entry barriers through family reunification programs (policy channel). This paper presents a microfounded identification strategy allowing to disentangle the relative importance of these two channels. Our empirical analysis exploits U.S. immigration data by metropolitan area and country of origin. We first confirm that the overall network externality is strong (the elasticity of migration flows to network size is around one). More interestingly, we show that only a quarter of this elasticity is accounted for by the policy channel for the 1990-2000 period, and the magnitudes of the total network effect and the policy channel are greater for low-skilled migrants. Our results are strongly robust to sample selection, identification assumptions, and treatment for unobserved bilateral heterogeneity. Finally, the policy channel was stronger in the 1990s than in the 1980s, possibly reflecting the changes in the U.S. family reunification policy. [less ▲]