26 Nov A Meta-Analysis of the Literature on Climate Change and Migration
A Meta-Analysis of the Literature on Climate Change and Migration
CREA discussion paper
Center for Research in Economic Analysis, University of Luxembourg
Recent surveys of the literature devoted to climate change and migration empha- size the important diversity of outcomes and approaches of the empirical studies. In this paper, we carry out a meta-analysis in order to investigate the role of the vari- ous methodological choices of these empirical studies in finding some particular results concerning the role of climatic factors as drivers of human mobility. To that aim, we code 45 papers representative of the existing literature in terms of methodological approaches. This results in the coding of more than 80 variables capturing the methodology of the main dimensions of the methods. These dimensions include among others 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 finding 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 main methodological choices, such as the frequency of the data on mobility, the level of development of the covered area, the particular measures of human mobility and of the climate factors as well as the econometric methodology.
In this paper, we examine environmental change as a potential determinant of international migration. We distinguish between unexpected short-run factors, captured by natural disasters, as well as long-run climate change and climate variability captured by deviations and volatilities of temperatures and rainfall from and around their long-run averages. We start from a simple neo-classical model, which is augmented to include environmental change at origin in the form of amenities. We then test the model using a panel dataset of bilateral migration flows for the period 1960-2000, the time and dyadic dimensions of which additionally allow us to control for numerous time-varying and time invariant factors. Using our primary specification, having accounted for other well documented determinants of migration, we find no direct impact of climatic change on international migration in the medium to long run across our entire sample. These results are robust when further considering migrants returning home. Further conditioning our regressions upon origin country characteristics, we find evidence that shortfalls in precipitation constraint migration from developing countries which rely more heavily upon agriculture and spur movements from developing countries with fewer groundwater reserves. We further use the rate of urbanization as a proxy for internal migration and find strong evidence that natural disasters beget greater flows of migrants to urban environs.
Ahmed, A.U., Hassan, S.R., Etzold, B., Neelormi, S. (2012). “Where the Rain Falls” project. Case Study: Bangladesh. Results from Kurigram District, Rangpur Division. Report No. 2. Bonn: United Nations University Institute for Environment and Human Security (UNU-EHS).