Stephen J. Dubner and Steven D. Levitt in Slate:
What is economics, anyway? It’s not so much a subject matter as a sort of tool kit—one that, when set loose on a thicket of information, can determine the effect of any given factor. “The economy” is the thicket that concerns jobs and real estate and banking and investment. But the economist’s tool kit can just as easily be put to more creative use.
Consider, for instance, an incendiary argument made by the economist Amartya Sen in 1990. In an essay in the New York Review of Books, Sen claimed that there were some 100 million “missing women” in Asia. While the ratio of men to women in the West was nearly even, in countries like China, India, and Pakistan, there were far more men than women. Sen charged these cultures with gravely mistreating their young girls—perhaps by starving their daughters at the expense of their sons or not taking the girls to doctors when they should have. Although Sen didn’t say so, there were other sinister possibilities. Were the missing women a result of selective abortions? Female infanticide? A forced export of prostitutes?
Sen had used the measurement tools of economics to uncover a jarring mystery and to accuse a culprit—misogyny. But now another economist has reached a startlingly different conclusion. Emily Oster is an economics graduate student at Harvard who started running regression analyses when she was 10 (both her parents are economists) and is particularly interested in studying disease. She first learned of the “missing women” theory while she was an undergraduate…