Black Death, savior
In the Middle Ages, Europe was arguably lagging behind its competitors to the East. So how did European nations come to dominate after the Middle Ages? According to a recent study, the answer is death, and lots of it. First, the Black Death, by killing a large fraction of the European population, allowed survivors to earn much higher wages, which allowed them to spend more on manufactured goods from cities and towns, spurring urban growth. Alas, this caused more death, because urban areas were overcrowded, disease-ridden “death-traps.” On top of that, increased trade spread more disease, and Europe was constantly at war, with armies causing deaths mainly by spreading disease, too. As the authors of the study put it, these “Horsemen of the Apocalypse effectively acted as ‘Horsemen of Riches’...because they jointly increased mortality, preserving post-plague wage gains.”
of the economy
Although China suffered many deaths from the plague, too, its cities were cleaner and it wasn’t at war all the time, so it didn’t get the same creative destruction that Europe did.
Voigtländer, N. & Voth, H.-J., “The Three Horsemen of Riches: Plague, War, and Urbanization in Early Modern Europe,” Review of Economic Studies (forthcoming).
In the ‘Twilight’ series of books and movies, vampires are depicted as unnaturally attractive, with the main vampire character confessing: “I’m the world’s most dangerous predator. Everything about me invites you in.” New research from psychologists at Washington University in St. Louis appears to back this up: Vampire-like people really do know how make themselves alluring. Independent observers rated the attractiveness of full-body-length photos of people in either a normally adorned state or an unadorned state with basic clothing, no makeup or accessories, hair pulled back, and a neutral facial expression. Each of what are known as the Dark Triad traits—Machiavellianism, narcissism, and especially psychopathy—was associated with significantly more attractiveness in the adorned state relative to the unadorned state. In other words, villainous people were the best at making themselves hotter.
Holtzman, N. & Strube, M., “People with Dark Personalities Tend to Create a Physically Attractive Veneer,” Social Psychological and Personality Science (forthcoming).
Have stocks, will vote
Republicans are known for advocating both for an “ownership society” and for tighter standards on voting. However, the results of a recent study suggest that at least in one context, these two objectives may conflict. Voter participation was associated with owning stocks, even with various controls for wealth, income, education, occupation, age, race, gender, political affiliation, union membership, religion, risk tolerance, IQ, investor sophistication, and socializing. Indeed, political “battleground” states were found to have significantly more people who own stock. This association was largely explained by voters’ greater interest in the news, which often includes information relevant to investing.
Bonaparte, Y. & Kumar, A., “Political Activism, Information Costs, and Stock Market Participation,” Journal of Financial Economics (forthcoming).
In friendship, class
Previous research has found evidence that teenagers tend to have friends with similar genes, in particular a gene related to neurological function and linked to political ideology and smoking. But new research suggests that such genetic friending isn’t a sign of some magical ability to sort ourselves by genes; it’s contingent on the social hierarchy. Only in schools with high inequality in socioeconomic status—as measured by mothers’ education—did teenagers tend to have friends with the same genes. According to the authors of the study, “one causal mechanism that could lead to such a finding would be that highly unequal schools tend to institute academic tracking policies.”
Boardman, J. et al., “How Social and Genetic Factors Predict Friendship Networks,” Proceedings of the National Academy of Sciences (forthcoming).
The unemployment unbenefit
In trying to ease the pain of the Great Recession, one of the few things Congress has been able to agree on is extending unemployment benefits. Ironically, one effect of these benefits may have been to make unemployment worse. A study by an economist at the Federal Reserve finds that extensions of unemployment insurance by Congress increased the unemployment rate by 1.4 percentage points, almost a third of the total increase in unemployment from the recession. The theory is that unemployment insurance—while helping families make ends meet—eases the pressure to find a job.
Nakajima, M., “A Quantitative Analysis of Unemployment Benefit Extensions,” Journal of Monetary Economics (forthcoming).
Kevin Lewis is an Ideas columnist.
He can be reached at