THE WALL STREET JOURNAL has an article about Steven Levitt, an economist who noticed that a precipitous drop in crime rates in the 1980s occurred 18 years after the Roe v. Wade decision; and that, furthermore, the five states that made abortion legal around 1969 experienced crime rate decreases at that same time.

Did crime fall because hundreds of thousands of prospective criminals had been aborted? Once again, the pattern by itself is not conclusive, but once again Mr. Levitt piles pattern on pattern until the evidence overwhelms you. The bottom line? Legalized abortion was the single biggest factor in bringing the crime wave of the 1980s to a screeching halt.

Levitt piously notes that, although this connection between abortion and lower crime rates is unpleasant to think about, we cannot dismiss its validity simply because of that unpleasantness: "Mr. Levitt repeatedly reminds us that economics is about what is true, not what ought to be true."

Of course, there is another truth, of which Levitt, if he is as eminent in his field as the WSJ contends, ought to be aware: Correlation is not causation. Given that women who have abortions are likely to be women (or girls) who do not want children or whose lives are too chaotic or unstable to have children, perhaps the drop in crime rates can be traced to fewer children living under these conditions. I haven't done the research, so I don't know if this is the case, but I am very suspicious of making a causal connection between a societal phenomenon as complex as crime rates, and any one single factor.