The kids are, eh, all right. A new poll from the Pew Research Center shows that more people now consider adequate income and an equitable division of household labor more essential to a happy marriage than having children. Researchers asked more than 2,000 adults what they considered important for a successful union; having children ranked eighth out of nine choices, ahead of only “agreement on politics.” Just 41 percent said that kids were “very important”—a plunge of 24 percentage points since the last such study, in 1990. (“Sharing household chores” shot up 15 percentage points over the same period, landing in third place.) The report attributes the shift in part to a change in moral thinking that has also led to greater social acceptance of cohabitation, premarital sex, and unwed childbearing. As a result, the authors say, “In the United States today, marriage exerts less influence over how adults organize their lives and how children are born and raised than at any time in the nation’s history.”
—“As Marriage and Parenthood Drift Apart, Public Is Concerned About Social Impact,” Pew Research Center
One hundred thirty-five years ago, Charles Darwin wondered whether pride led to good posture, or whether it was the other way around—that a ramrod back inspired self-confidence. A little of both, says a new study—but only for men. The authors asked participants to take a math test while sitting either slumped or upright; they found that men felt better about their performance on the test if they sat upright. Women, however, felt more confident about their performance if they slouched. The men who’d been sitting up straight went on to score better than their hunched counterparts; the women’s scores showed no such disparity. The authors suggest that men rely more on internal cues when determining how they feel and that women rely more on external ones—an upright posture forces them to be more self- conscious, which previous studies have shown can hurt how well they do on math tests.
—“Not All Who Stand Tall Are Proud: Gender Differences in the Proprioceptive Effects of Upright Posture,” Tomi-Ann Roberts and Yousef Arefi-Afshar, Cognition and Emotion
Don’t blame the collapse of the Soviet Union for the widespread popularity among arms dealers and insurgents of the AK-47 Kalashnikov assault rifle, a new study on “weaponomics” advises. Blame the Soviets: Not only has the AK-47 been widely copied, but “large caches of these weapons were freely distributed to regimes and rebels sympathetic to the Soviet Union” well before its collapse. Drawing on field reports and journalistic accounts, the study claims to be the first effort to quantitatively document the market for small arms, which are responsible for between 200,000 and 400,000 deaths each year. The AK-47 merits particular attention because its “ease of operation, robustness to mistreatment and negligible failure rate” make it the weapon of choice for small armies and bands of marauders: Of the 500 million firearms estimated to be in the world today, some 100 million are Kalashnikovs. The study reports that assault rifles are on average at least $200 cheaper in a typical African country than elsewhere, thanks to porous borders (as conflict moves across the continent, the arms freely follow). It also finds that the small-arms trade tends to be weaker in countries with high military spending, because a strong military makes it “imprudent for non-government entities to openly trade or parade about with large quantities of conflict-grade weapons.” Most surprisingly, the study cites research suggesting that having more arms in the marketplace makes running a counterinsurgency easier, presumably because it tends to fragment rebel groups: “The more easily individual combatants can obtain weapons through independent suppliers,” the author writes, “the more difficult it will be to mount and maintain a united and coordinated insurgency.”
—“Weaponomics: The Global Market for Assault Rifles,” (PDF) Phillip Killicoat, World Bank Policy Research Working Paper
When NBA Commissioner David Stern acknowledged in July that referee Tim Donaghy may have gambled on games he officiated, Stern called him a “rogue, isolated criminal.” But a paper by an undergraduate student in the Stanford Department of Economics suggests that Donaghy may not have been a rogue element after all—there’s a distinct likelihood, the author argues, that NBA players (or coaches) are also betting on games. The author observes that conventional economic theory supports conflicting claims about pro basketball’s betting market: On the one hand, that market displays a measure of inexplicable irrationality that typically would point to untoward business transactions (like insider trading); on the other hand, NBA players make so much money that the odds of their intentionally shaving points, and thus jeopardizing their careers, seem quite slim. Still, pro ballplayers may not be immune to the lures of the sports book, given the brevity of their careers, their willingness to put personal interest ahead of team success, and their drive to compete, which they share with gamblers. The author studied betting lines and game results from the previous 14 NBA seasons and then analyzed how scores tended to move in a game’s last five minutes—to his mind, the period when it was easiest to cheat. He found that heavily favored teams failed to cover the spread often enough to suggest that some funny money may have crept into the market. He estimates that players or coaches on the take skew perhaps five games a season, adding that since “referees are no less principal characters in basketball games,” future researchers might investigate whether there are more bad apples in the officiating ranks.
—“Point Shaving in the NBA: An Economic Analysis of the National Basketball Association’s Point Spread Betting Market,” (PDF) Jonathan Gibbs, Stanford Department of Economics
Maybe it’s time to rethink what we mean by the “golden years.” As Americans get older, they tend to make better and better financial decisions—but only up to a point, a study finds, and then their hard-earned skills decline. Researchers from Harvard, Princeton, and the Federal Reserve—drawing on consumer financial data from 10 sources, including mortgages, credit cards, and car loans—observed an overall U-shaped pattern of financial mistakes, with the best performance occurring among people in their early 50s. On average, financial perspicuity peaks at 53, which the study designates the “age of reason.” The age of peak discernment when it comes to picking the best home-equity loan is 56; for a mortgage, it’s 62, and for a car loan, it’s 50. Both older and younger borrowers are more apt to make poor decisions that result in higher interest rates and fee payments. The researchers (all on the cusp of middle age themselves, incidentally) suggest that the financial acumen of 50-somethings demonstrates that experiential capital trumps the analytical capital that quick-thinking youngsters enjoy, but that it follows a pattern of diminishing returns as old age encroaches.
—“The Age of Reason: Financial Decisions Over the Lifecycle,” Sumit Agarwal, John C. Driscoll, Xavier Gabaix, and David Laibson, MIT Department of Economics Working Paper