Will Climate Change Push Mexicans North to the US?

The potential demographic consequences of climate change have been difficult to assess, but a new study published in the Proceedings of the National Academy of Sciences (PNAS) suggests that climate change could force residents of Mexico to go north in search of jobs. Shuaizhang Feng, Alan B. Krueger, and Michael Oppenheimer, all of Princeton University, have generated a model that simulates the drop in crop yield associated with projected global warming, and then projects the number of Mexicans working in agriculture who would be forced out of the country if crop yields dropped:

Depending on the warming scenarios used and adaptation levels assumed, with other factors held constant, by approximately the year 2080, climate change is estimated to induce 1.4 to 6.7 million adult Mexicans (or 2% to 10% of the current population aged 15–65 y) to emigrate as a result of declines in agricultural productivity alone.

The model is very complex and incorporates a great many assumptions with which you might or might not agree. Indeed, an initial reaction to the publicity about this study was alarm on the part of some people in the US who want to cut off immigration from Mexico, rather than absorb new immigrants. But there is a great deal of food for thought in this analysis and it deserves our careful analysis.

Demographic Rebirth After the Rwandan Genocide

In 1994, a genocidal war between Tutsis and Hutus left an estimated 800,000 Rwandans (about 20% of the population) dead. Victims were overwhelmingly men, and the demographic fallout has been that women have led the effort to rebuild the country. A story on America Public Media's Marketplace takes a look at the rebirth of Rwanda:

Rwanda's the only country in the world where women outnumber men in Parliament. Just 10 years ago women weren't allowed to own land or keep their assets separate from their husbands. Now they can. And Rwanda now has a special police unit to stop domestic violence. The government is also trying to draw more women out of the house and into the work force. All over this very Catholic country you'll find family planning clinics.

In many ways, this could be one of the most important demographic revolutions in the modern world.

Will Iranians Respond to the Government's Pronatalist Policies?

Iran has one of the lowest levels of fertility of any Muslim-majority country, helped along by a long-term government policy aimed at keeping family size at two children in order to promote economic development. This situation has bothered Iranian President Ahmadinejad ever since he was first elected to office in 2005. His view is that population growth is good, not bad, and the New York Times has reported that the government of Iran has implemented a pronatalist policy aimed at encouraging childbearing:

Under the new plan, each child born in the current Iranian year, which began March 21, will receive a deposit of $950 in a government bank account. The child will then receive $95 every year until reaching 18. Parents will be expected to pay matching amounts into the accounts. Recipients will then be permitted to withdraw the money at the age of 20 and can use it for education, marriage, health or housing.

It is not clear that the government can really afford this if a lot of couples took them up on it, nor is there much evidence from past experiences in other countries that this kind of incentive will be taken up by enough women to really make a demographic difference. Even more importantly, there is not yet any sign that the government has pulled back on the provision of contraception--that might well cause another set of protests.

Hans Rosling on Population Growth

Using Ikea containers as props, Hans Rosling, Professor of International Health at Karolinska Institute in Sweden, explains population growth between 1960 and 2050. Check it out.

Japanese Women are Living Even Longer

Japanese women have been the longest-lived of any group of people for many years now, and a new report from the Japanese Ministry of Health, Labor and Welfare (reported by the Associated Press) show that they have extended their lead even further, up to a life expectancy of 86.5 years. Japanese men are not #1, however, and indeed they have slipped from 4th to 5th in the world rankings, apparently because of an increase in suicide among older men. The AP story suggests that longer lives among women might be a problem because of the increasing number of older people, but in fact it is probably a good thing because--given the very low birth--it will slow down the process of depopulation in Japan.