We have evolved with a tendency to link causality to things we can touch or feel, not to some distant or difficult phenomenon. We believe especially in near-term causes: a snake bites your friend, he screams with pain, and he dies. The snakebite, you conclude, must have killed him. Most of the time, such a reckoning is correct. But when it comes to cause and effect, there is often a trap in such open-and-shut thinking. We smirk now when we think of ancient cultures that embraced faulty causes-the warriors who believed, for instance, that it was their raping of a virgin that brought them victory on the battlefield. But we too embrace faulty causes, usually at the urging of an expert proclaiming a truth in which he has a vested interest. How, then, can we tell if the abortion-crime link is a case of causal- ity rather than simply correlation? One way to test the effect of abortion on crime would be to mea- sure crime data in the five states where abortion was made legal before the Supreme Court extended abortion rights to the rest of the coun- try. In New York, California, Washington, Alaska, and Hawaii, a woman had been able to obtain a legal abortion for at least two years before Roe v. Wade. And indeed, those early-legalizing states saw crime begin to fall earlier than the other forty-five states and the District of Columbia. Between 1988 and 1994, violent crime in the early- legalizing states fell 13 percent compared to the other states; between 1994 and 1997, their murder rates fell 23 percent more than those of the other states. But what if those early legalizers simply got lucky? What else might we look for in the data to establish an abortion-crime link? One factor to look for would be a correlation between each states abortion rate and its crime rate. Sure enough, the states with the high- est abortion rates in the 1970s experienced the greatest crime drops in