When Nature Rebels: International Migration, Climate Change, and Inequality

By combining economic models with environmental knowledge, the authors of this study sought to create an analysis of international human migration that encompassed policy responses to the issue. A two-country overlapping generations model with endogenous climate change measured on a scale of steady state perspective was used to accomplish this end. The authors summarize their main findings as follows: change in climate creates an increase in migration, small levels of climate change result in substantial impacts on the number of migrants, northern immigration policies have the potential to impact long-run migration thus impacting regional inequality, and finally that green technology decreases emissions and long-run migration where the migrant impact to climate change is significant. A consideration of how values of inequality, wealth, environment, and migration numbers impact policy development is also widely discussed. Although the authors caution the limitations of their approach, they ultimately advocate that their model may provide states with guidelines for how to best distribute tax revenue in regard to the issue of human migration. –Adriane Holter

Marchiori, L., Schumacher, I., 2011. When nature rebels: international migration, climate change, and inequality. Population Economics 24, 569–600.

          In an environmental review, the authors remind that while the developed world is responsible for the vast majority of CO₂ emissions, it is the developed world that will experience 80% of the lived damage of global climate change. These experiences include areas such as the loss of agricultural productivity and water quality, which result in unsustainable living conditions, that oftentimes lead to environmentally motivated migration. Reasons for movement out of an area also may include anticipation of deteriorating and therefore non-sustainable living conditions. The economic model used in the study incorporates concerns of livelihood by presenting a decision calculus that states when a person (referred to as “generations”) considers the benefit of migration to be greater than that of staying at home, then that person will migrate. The firms in the model are stated as operating on the basis of profit maximization in a perfectly competitive market where they have access to international capital mobility.

          The authors present four propositions that result from their analysis, many of which have important policy implications. First, the optimization consideration of firms and the relative situation of the generations, an integrated approach is similar to one of autarky, indicating the economic independence of the firm. Second, endogenous climate change is a large contributor to international migration that effectively diminishes the per capita welfare of both northern and southern regions. Third, increased allocation of funds toward border controls reduces southern access to migration and increases northern control. This relationship has the ability to either exaggerate or lessen current north-south regional inequalities due to environmental improvements and long-run migrant numbers. Finally and similar to the third proposition, an increase in taxes allocated to green technology will potentially decrease migrant numbers, positively impact the environment, and alter the relationship between north-south inequality.

          Based on these propositions, the authors posit that it is advisable for Europe to increase the allotment of tax revenue toward immigration costs than North America. Conversely, North America should invest more tax revenue in green technology than Europe. This inverse economic relationship is due to the fact that production in North America creates substantially larger numbers of CO₂ emissions than its European counterpart and therefore may best benefit from new environmental policy. Additionally, North America currently employs harsh restrictions on border control policy. Europe’s comparatively “soft” immigration policy therefore makes new approached recommendable.