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.

The Language Demographic

The Wall Street Journal carries a story by Dr. Lera Borodistsky, a Professor of Psychology at Stanford, discussing the potential role that language plays in the way we think and perceive the world. This has obvious implications for the connection between culture and demography, and flies in the face of the well-entrenched theories of Noam Chomsky that language is universalistic and is not tied to specific cultures. Professor Borodistsky's view of the world seems to be shared by Indonesians who, according to the New York Times, are very worried about the fate of their language as Indonesian elites focus on teaching their children English from an early age. This is a tricky area in which to work, of course, because we need to always be wary of falling into the trap of thinking that language determines behavior. More likely, it helps to shape behavior in subtle ways.

Will Ethiopia be Saved by China?

Ethiopia has one of the world's most rapidly growing populations, yet is mired in poverty, despite billions of dollars in aid money. The Economist has recently reviewed a new book on Ethiopia that takes a critical look at the progress, or lack thereof, that the country has made under the 20 year rule of Meles Zenawi (Famine and Foreigners: Ethiopia Since Live Aid, by Peter Gill, London:OUP). Two things stand out in the review: (1) "The most menacing problem, Ethiopia's rapidly growing population, is almost never discussed;" and (2) the Chinese have become an important presence in Ethiopia, as they have elsewhere in Africa, and Gill suggests that Ethiopia may be saved by China. At the same time, however, the reviewer notes that "the Chinese might be building a lot of roads, but it is not at all evident that they are helping to tackle the issues of land [the persistence of small landholdings that are under-productive] and population.

Dengue Fever Lurks in Florida

Back in 1935, Hans Zinsser reminded us that diseases are constantly lurking, waiting to take advantage of a moment when we let our guard down. I thought of this when reading reports of recently diagnosed cases of Dengue Fever in Key West, Florida. The island has a population not only of humans, but also of Aedes aegypti mosquitos, which are the vectors that spread the virus among humans. Thus it only would have taken one infected person, or the arrival on a plane of one infected mosquito, to spread the disease. A colleague of mine, Dr. Arthur Getis, has been studying the spatial demography of Dengue Fever for a long time and has published many articles on the topic, including an analysis in another Florida (this one in Puerto Rico), where the recommendation was that control measures needed to include the entire municipality, not just the places where known cases had been identified.

Would Vegetarianism Save the Planet?

I have argued that if more people were vegetarian, we could free up agricultural land to grow food directly for human consumption, rather than growing food for animals that are then slaughtered for food. Tim Harford has noted that there is another beneficial environmental consequence of a higher level of vegetarianism: It would lead to a lower level of greenhouse gas emissions from the animals that are being raised for food. Even more importantly, there is an enormous environmental cost associated with transporting meat from slaughterhouse to market. Think about that the next time you order a Big Mac.

People, Cars, and Energy

For many centuries China has been the most populous nation on earth. It has now reached two more milestones of potentially dubious, but still very important, distinction: (1) General Motors sold more cars in China in the first half of 2010 than they did in the United States, according to a story in the New York Times; and (2) the U.S. International Energy Agency reports that China has now overtaken the United States as the world's largest consumer of energy. These three things are obviously interrelated--more people, more cars, more energy consumption.

Water Dispute Between India and Pakistan

India and Pakistan both have rapidly growing populations and they share the water of the Indus River through a treaty signed many years ago. However, the New York Times reports that India's construction of hydroelectric dams along the river has created new tension between the countries. Pakistan feels that the dams will give India control over the water flow that will leave Pakistan vulnerable to having its water supply manipulated by India. Since the amount of water is unlikely to increase, whereas the populations of both countries are projected to grow enormously between now and the middle of this century, this situation is likely only to worsen over time.

Reducing the Risk of HIV Infections for African Women

African women are often victimized by HIV-positive men who insist on having sex without using condoms. There is, however, a set of encouraging results in South Africa from a trial of a vaginal microbicidal gel called tenofovir that at least reduces the risk of transmission if a woman use the gel immediately before and after intercourse. Still, these are early days and the risk reduction is only 39% (although it is 54% for the most dedicated users) compared to women using a placebo.

Organizational Inefficiency in Pakistan

Pakistan has one of the highest rates of population growth in the world, and one of the highest levels of poverty. It is a country that desperately needs as much help from within as it can get. Yet, a report in the New York Times refers to a new study in Pakistan showing that the wealthiest Pakistanis are not paying taxes. This is the kind of organizational inefficiency (aka "corruption," even if technically legal) that limits the ability of an economy to develop and meet the needs of its citizens.

Guatemalan Rain Forest is Threatened

Demographers such as David Carr-Lopez have written extensively about the threats to the Guatemalan rain forest from peasants who move onto reserved land and cut down trees to sustain their own families. Now comes a much larger threat, according to the New York Times, which reports that Mexico-based drug barons have taken over large chunks of reserved rain forest and are chopping down trees in order to create large cattle ranches. The government is struggling to force them out. Richard D. Hansen is an Idaho State University archaeologist who is leading the excavation of the earliest and largest Mayan city-state, El Mirador, in the northern tip of the reserve. He reminds us that the risks of not protecting the region are obvious in every stone unearthed. The Maya, he said, "largely sealed their fate through deforestation and erosion.The Maya destroyed their environment. They cut down their jungle and it ruined them forever. And we’re doing the same thing today.”

Border Crossing Deaths

My son, Gregory Weeks, has posted to his blog about the increase in deaths among undocumented immigrants crossing the border into Arizona.

Non-Metro US Troops Have Higher Mortality in Iraq

Kathryn Curtis and Collin Payne have published a fascinating analysis of mortality among US troops in Iraq that shows that soldiers from non-metro areas in the US have higher death rates in Iraq than those from metro areas, even after controlling for other relevant factors. They are not able to say exactly why this difference exists, but the difference will almost certainly lead to follow-up research. Beyond its potential political importance, the paper offers excellent insights into using non-standard data to generate demographic knowledge.

Maternal Mortality tied to Unsafe Abortions in Ghana

Although abortions are legal under some circumstances in Ghana, many women appear to be unaware of that fact, and there is anecdotal evidence that providers often discourage women from seeking a legal abortion. A new report from the Guttmacher Institute summarizes information gleaned from the 2007 Ghana Maternal Health Survey, revealing that more than one in ten maternal deaths in Ghana is the result of an unsafe abortion. Many more women suffer complications from the procedure, even though they survive. Abortion rates are highest among younger women, the better educated, those living in cities, and higher among Christians than Muslims.

US Census 2010 Winding Down

The official census day in the United States is always the 1st of April, but in fact the counting started in January 2010 in Alaska, and in the middle of July 2010 the in-person followup of nonresponding households was winding down, putting a lot of temporary census workers out of work, as reported by the New York Times. Because of the recession, the Census Bureau was able to hire an unusually talented group of temporary workers and, of course, we can hope that this will help to maintain high quality results. You can keep up with the progress of the census through the periodic blog postings from the Director of the Census, Dr. Robert Groves.

Malaria Buzz

The Wall Street Journal has a teaser article by Sonia Shah, who has a new book out on The Fever: How Malaria Has Ruled Humankind for 500,000 Years (New York: Sarah Crichton Books/Farrar, Straus & Giroux, 2010). Although spraying and drugs and other measures have lowered the death rate from malaria, especially since the end of WWII, the parasite and its mosquito vector are incredibly tenacious, and humans, she argues, are part of the problem--we are often way too careless or simply fatalistic (no pun intended) about malaria.

Targeting Employers of Undocumented Immigrants

The Obama administration is quietly trying to deal with undocumented immigration by conducting silent raids of companies in which they audit records to determine which workers are here legally and which are not, and the undocumented workers are fired on the spot. The employers then claim that they are left without workers, while some members of Congress complain that the policy is too lax—it leads to workers being fired, but not deported—at a time when Americans are desperately seeking jobs. Somehow these two perspectives seem to be miles apart.

Undocumented Immigrants in Israel

The Israeli population is growing more slowly than the Palestinian population and this has created labor shortages in Israel that were once met by Palestinians, but since the intifada, the New York Times reports that Israel has imported workers from elsewhere in the world, especially Asia, and is now facing the problems of illegal immigrants, human trafficking, and the exploitation of foreign workers. This adds a whole new demographic dimension to the human drama in this volatile region.

World Population Day

The 11th of July was World Population Day, as declared by the UNFPA. The United Nations is emphasizing the importance of responding to the census as we move into a new decade of census-taking, whereas USAID naturally emphasizes the family planning programs that it supports as a way of empowering couples to have no more children than they want. This is probably as close as either organization wants to get to endorsing anything that might be thought of as a population policy.

Porcelain parity

For most of human history, people went to the “bathroom” by squatting in the brush somewhere, and for this it did not matter much whether you were male or female. But in modern urban settings we need plumbing facilities to accommodate the different needs of males and females and The Economist has reported on the world wide efforts to level of public bathroom facility playing field (what it calls “porcelain parity”) for men and women around the world—all as part of the move toward improved gender equity.