Relaxing international barriers to migration would greatly expand the adaptation opportunities for people who are vulnerable to negative shocks from climate change. That is the key takeaways from a new working paper by Klaus Desmet and Esteban Rossi-Hansberg, “On the Spatial Economic Impact of Global Warming” (pdf). The paper was the focus of a Free Exchange column (and blog) last month — a column we blogged about here as well. Desmet and Rossi-Hansberg recently summarized their findings at VoxEU:
There are two ways to deal with climate change: mitigation and adaptation. This column argues that in order to adapt, we need to take another look at an age-old coping mechanism: migration. Indeed, if overall hotter temperatures lower productivity in hot regions but raise productivity in what are currently cooler regions, the negative economic effects of climate change are likely to stem from frictions preventing the movement of people and goods. Without these frictions, adapting to climate change becomes that much easier. Climate change policy ought to aim at alleviating mobility frictions.
If barriers to international migration remain high, adaptation will pose an even more serious challenge. But many developing countries will still have options, particularly in regards to internal migration. In regions where the negative impacts of climate change will be least severe — or possibly even beneficial — countries can facilitate adaptive migration by making room for the expansion of existing urban areas or even starting new cities. Matt Kahn and I touched on these ideas in our piece for VoxEU, “Climate adaptation through migration: a role for charter cities.”