Joel Cohen does the math on human migration worldwide

Every year, millions of people migrate from one country or continent to another. Joel Cohen’s mathematical models are used to map patterns in human migration.

Joel Cohen: We know that about 200 million people, or just under 3%, of the world population are living outside the country in which they were born.

That’s Joel Cohen of Rockefeller University. He uses mathematical models to map present-day human migration around the globe.

Joel Cohen: Most international migration goes to a rather small number of wealthy countries — for example, the United States, Canada, Argentina, Australia…

Cohen said one surprising finding was that the bigger the population of the destination country, the larger the number of immigrants.

Joel Cohen: And the boundaries between countries have simply become much more porous. As part of that movement of ideas and information, people have recognized that they can do better for themselves elsewhere.

Cohen said knowing just how many people are moving where is vital for future policy planning.

Cohen: It’s important to have a good picture of the demographic future to aid nations in planning for examples for pensions, for schools and education systems, for jobs and employment, for health and for defense, among other important challenges.

That means, as birthrates continue to fall around the world, borders will be as important keep up with as newborns, if we want to accurately track population trends.

Every year, millions of people migrate from one country or continent to another. Joel Cohen’s mathematical models are used to map patterns in human migration.

Joel Cohen: To our surprise, we found that the density of the destination country plays no statistically significant role in the number of immigrants to that destination. In other words, it doesn’t matter, apparently, how crowded the country is that people are going to. That’s not what they’re interested in.

Migration affects not only the lives of migrants, Cohen said, but of all people in communities large and small.

Joel Cohen: If you look at the discussions about migration in the United States, you can see that it offers opportunities for migrants, but it also supports the communities into which people migrate by providing workers in jobs that need to be filled and providing creativity and talent, specialized skills.

Our thanks to:
Joel Cohen
Rockefeller University
New York, NY

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