Research press release


Nature Climate Change

Demographic changes mitigate impacts in those who do not migrate


今回、Soheil Shayeghは、開発途上国における気候変動と人口構造の変化と国外移住の総合評価モデルを作成した。その結果分かったのは、技能を有する者の方が移住のチャンスが大きく、子の教育に対する投資額を増やすことへの親の意欲が高まり、子の総数を減らす傾向が生まれていることだ。しかし、外国へ移住できるのは、技能を有する子の一部にすぎない。そのため、移住せず本国に残留する労働者の技能構成が変化し、所得の不平等による格差が縮まる。つまり、熟練労働者の需要が減って、その賃金水準が下がり、未熟練労働者の需要が増して、その賃金水準が上がるのだ。


The need to migrate due to climate change may change demographic patterns in developing countries, ultimately reducing local income inequality among those who do not migrate, according to research published online this week in Nature Climate Change. The study suggests that migration can mitigate the some of the negative consequences of climate change through demographic changes, rather than by movement of people alone.

Soheil Shayegh created an integrated assessment model of climate change, demographic change, and migration in developing countries. He finds skilled individuals will have greater migration opportunities, creating incentives for parents to invest more in educating their children, while also having fewer children in total. However, only a portion of skilled children are able to emigrate. This changes the skill composition of non-migrating workers and closes the income inequality gap, as demand for skilled workers decreases - so their wages decrease - and demand for unskilled workers increases - so their wages increase.

The author suggests that previous work on migration focuses on how migration can mitigate climate-change damages by moving people from vulnerable to less vulnerable locations. By modelling impacts of migration on fertility (the number of children a woman has), the author demonstrates how migration can also lessen negative consequences of climate change through demographic changes among poor and agricultural workers who are unable to afford emigration.

doi: 10.1038/nclimate3420


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