Forget SUVs and tractor-trailers—the world’s livestock play a larger role in global warming than all of our planes, trains, and automobiles combined, according to a report from the Livestock, Environment and Development Initiative (LEAD), an organization that promotes “ecologically sustainable livestock production systems.” Between the deforestation that’s necessary to create grazing lands, the fossil fuels required to manufacture fertilizer for the crops that feed the world’s growing livestock population, and the gases released by animal manure (and yes, animal flatulence as well), livestock are responsible for 18 percent of greenhouse-gas emissions worldwide. The good news: There are ways to reduce these emissions, including more efficient feed production, improved soil conservation, and a better diet for all those gassy cows. Given that the global production of meat and milk is on track to double by 2050, livestock’s current environmental impact would need to be cut in half just to stay within the present level of damage to the global ecosystem.
—“Livestock’s Long Shadow,” Livestock, Environment and Development Initiative, H. Steinfeld et al.
Between 1960 and 2000, the employment rate for black men plunged from 90 percent to 76 percent; for “low-skilled” black men (defined as high-school dropouts), in particular, it fell from 89 percent to just 56 percent. Between 1980 and 2000, meanwhile, the incarceration rate for black men rose from just 1 percent to nearly 10 percent. A new study considers this shift in light of large-scale immigration, which may have crowded black men out of the labor market and made a shift to crime more appealing. The researchers found that as immigration increased the supply of workers at a particular education level, the employment rate for black men in that category declined, and the incarceration rate rose. From 1980 to 2000, the authors conclude, immigration accounted for roughly a third of the decline in the black employment rate, and about 10 percent of the increase in the incarceration rate for low-skilled African Americans.
—“Immigration and African-American Employment Opportunities,” George J. Borjas, Jeffrey Grogger, and Gordon H. Hanson, National Bureau of Economic Research
Does antismoking advertising work? Not if it’s funded by tobacco companies, argues a new study that examines three such ad campaigns. The authors found that, on average, each additional youth-targeted prevention ad that a young person saw was associated with a 3 percent stronger intention to smoke at some point in the future. Exposure to prevention ads targeted at parents, meanwhile—like the Philip Morris campaign urging parents to “Talk. They’ll Listen.”—made older teens less likely to perceive smoking as harmful, more likely to approve of smoking, and more likely to plan to smoke in the future. In these ads, the authors note, “no reason beyond simply being a teenager is offered” to explain why kids shouldn’t smoke, which dovetails with Philip Morris’s stated aim of delaying smoking, not preventing it.
—“Effect of Televised, Tobacco Company-Funded Smoking Prevention Advertising on Youth Smoking-Related Beliefs, Intentions, and Behavior,” Melanie Wakefield et al., American Journal of Public Health
The divorce rate in America peaked thirty years ago and has declined slightly since—but not for everyone, a study by a sociologist at the University of Maryland points out. A woman’s likelihood of divorcing within ten years of her first marriage rose irrespective of her level of education until the mid-1970s. But after that, divorce rates diverged. Twenty-nine percent of women with a four-year college degree who married between 1975 and 1979 divorced within a decade; among college-educated women who married between 1990 and 1994, the within-ten-years divorce rate had fallen to 16.5 percent. Among women with only a high-school diploma, however, the divorce rate remained roughly constant over the same period, and it rose among women without a high-school diploma. This divorce divide, the author suggests, might be both a consequence and a cause of America’s growing economic inequality. Economic disadvantages can make divorce more likely, and divorce in turn creates further personal and financial difficulties for parents and children alike, which threaten to “perpetuate inequality across generations.”
—“Trends in Marital Dissolution by Women’s Education in the United States,” Steven P. Martin, Demographic Research
The list of consumer goods that Americans claim they can’t live without just keeps getting longer, according to a new survey from the Pew Research Center, which tracks the percentage of Americans who rated various items as “necessities” in 1996 versus 2006. Some of the newly necessary products on the ‘06 list weren’t even on the radar a decade before—high-speed Internet access, for instance, which 29 percent of respondents now can’t live without. But other items that made a leap toward widespread indispensability have been on the market for years or decades—dishwashers, for example, as well as microwaves, clothes dryers, and cable television. Manufacturers and advertisers can rest assured that once we start needing something, we never stop: The report notes that across the products surveyed, “wherever there has been a significant change ... in the public’s judgment about these items, it’s always been in the direction of necessity.”
—“Luxury or Necessity?” Pew Research Center
The Hashemite kingdom of Jordan is an oasis of relative calm in a chaotic region—and that might turn out to be a bad thing, warns a paper from the Carnegie Endowment for International Peace. American and European support for the Jordanian government, which is essentially an absolute monarchy under a constitutional veneer, represents “a classic case” of prioritizing strategic interests over political reform. But the repressive nature of Jordan’s government could harm the West’s strategic interests in the long run, the author argues. Unless some kind of democratic reform takes place, the various problems Jordan faces— “deterioriating conditions on its borders, a lack of tangible economic success, and an extremely unpopular foreign policy” (particularly its friendly relationships with Israel and the United States)—are likely to empower the country’s Islamist opposition and weaken the legitimacy of the government.
—“Illusive Reform: Jordan’s Stubborn Stability,” Julia Choucair, Carnegie Endowment for International Peace
Why do women fall off academia’s science track at a faster clip than men? The cause is not innate sex differences, a new study suggests, but neither is it a simple matter of gender discrimination. If a problem exists, the authors conclude, it’s about motherhood, not women in general. Using the 1973–2001 Survey of Doctorate Recipients, the study found that while women are less likely than men to enter tenure-track positions in the sciences, the difference is explained completely by “fertility decisions.” Single, childless women are between 11 percent (in the life sciences) and 21 percent (in the physical sciences) more likely to have a tenure-track job within five years of finishing their doctorate than single, childless men. Marriage and children, however, can give men an advantage. While married scientists of either gender are more likely than single scientists to be on the tenure track within five years, married men are 22 percent more likely than single men, while married women are only 5 percent more likely than single women. And children can hurt a woman’s chances significantly: Having a child of prekindergarten age took 8 percentage points off a woman’s chances of getting that tenure-track job. Mothers in science who do step onto the tenure track gain tenure and full professorship as quickly as non-mothers. But men always retain the edge: Each child of grade-school age in a male academic’s family actually increases by 3 percent the likelihood that the man will receive tenure. (Younger children have no effect on a man’s chances for tenure, and men’s promotion to full professorship is not affected by children of any age.)
—“Does Science Promote Women? Evidence From Academia 1973–2001,” Donna K. Ginther (University of Kansas) and Shulamit Kahn (Boston University)
Hard time is supposed to be hard. But a new study says harsher prison conditions also make criminals measurably more likely to offend again. The study tracks nearly a thousand people released from federal prisons in 1987. Those whose federal inmate classification scores just barely landed them in low-security (rather than the cushier minimum- security) lockup ended up back in the pokey nearly twice as often as inmates whose scores were slightly lower. The paper’s findings cast grave doubt on the value of at least one model of deterrence, which holds that a few years of grim prison conditions will spook criminals back onto the straight and narrow. Whatever the deterrent effects of harsh prison conditions, the authors conclude, they may often be outweighed by the increased criminal propensities of the prisoners subject to them.
—“Does Prison Harden Inmates?” M. Keith Chen (Yale University) and Jesse M. Shapiro (University of Chicago)
How do the world’s poorest citizens get by on less than $2 a day? A new paper examining the poor in Asia, Africa, and South America finds the expected litany of privations, along with a few surprises. Despite variance in living conditions—only 2 out of 100 poor rural Tanzanians had electricity, for example, but only 1 out of 100 equally poor rural Mexicans lacked electricity—poor people around the world reported high rates of sickness and infirmity and low rates of access to the financial infrastructure (formal loans, insurance, savings accounts) that might give them a firmer economic foothold. For the most part lacking steady employment, the poor were found to be remarkably entrepreneurial (nearly half of poor urbanites in Indonesia, Pakistan, and Nicaragua operated their own businesses), although debt remained a constant concern (94 percent of the Pakistani urban poor owed money). When poor people did have money to spare, they spent a surprising amount on entertainment (radios, TVs, weddings) and relatively little on food.
—“The Economic Lives of the Poor,” Abhijit V. Banerjee and Esther Duflo, Massachusetts Institute of Technology
A paper by three Austrian population experts takes up Europe’s falling birthrates, which have dropped below replacement level in many countries, and investigates whether they are likely to rebound, level off, or continue to fall. Current United Nations projections estimate that birthrates will level off at around 1.85 children per woman in most countries. But it’s just as likely, the authors argue, that Europe will find itself caught in a “low fertility trap” that keeps driving the Continent’s population downward. They cite three elements that might create this cycle of childlessness. First, there’s the negative momentum created by a declining population, in which fewer women enter their prime childbearing years every generation, and their lower numbers lead to fewer births overall even if the birthrate suddenly returns to replacement level—and many fewer if it doesn’t. Second, people who grow up in a largely childless society may internalize a much smaller “ideal family size” and have fewer children. And third, as the population of Europe ages, the income prospects of younger workers will likely decline, creating an age of diminished expectations that will lead young people to delay having children still further, or have none at all. The low-fertility trap, the authors caution, is only a hypothesis, but it’s plausible enough to deserve “serious consideration”—especially since it may soon be too late for government policies to reverse the possible downward spiral.
—“The Low Fertility Trap Hypothesis,” Wolfgang Lutz, Vegard Skirbekk, and Maria Rita Testa, International Institute for Applied Systems Analysis