Friday, August 10, 2007

Correlation Does Not Equal Cause [Bob]

John R. Lott Jr., of National Review offers an interesting report (August 13, 2007, p. 18) on the common claim among abortion supporters that abortion serves to lower crime rates. The data invoked to buttress this claim is the unexpected and rapid drop in violent crime that occurred between 1991 and 2000. Their argument goes like this:

  1. Aborted children are, by definition, "unwanted"
  2. Raised in an unwanted environment, children who could have been aborted will likely become criminals
  3. The 1973 Roe-v-Wade decision legalized abortion
  4. Children born subsequent to Roe reached adulthood in the early 1990s
  5. Because those children were "wanted" children, they were less likely to be criminals
  6. Therefore, violent crime dropped upon their reaching adulthood
This argument elicits three immediate responses.

First, so what? Even if it can be shown that more abortions lead to less violent crime, that fact would do nothing to answer the moral question around which the pro-life argument centers. The possibility of lowering crime rates sometime in the future does nothing to justify the taking of innocent human life now.

Second, it is amazing to see the height of the arrogance displayed by the deterministic assumption that the dismal, criminal future awaiting the "unwanted" rationalizes snuffing them out before birth. This makes Tom Cruise's "Pre-Crime" unit in Minority Report look tame by comparison. At least those pre-criminals were arrested and tried by those who claimed to know the criminal's future intentions. The aborted human fetus gets no such chance.

Third, there is no indication that the "violent crime" statistics include the millions of fetuses that were also victimized by premeditated homicide. Purely an oversight, I'm sure.

Those observations aside, Lott shows that the entire abortion-reduces-crime argument is a myth anyway. While there are plenty of alternative explanations ...

higher arrest and conviction rates, longer prison sentences, "broken windows" police strategies, the death penalty ... right-to-carry laws, a strong economy, or the waning of the crack-cocaine epidemic
... the real answer lies in the way abortion proponents choose to manipulate the data itself. The idea that abortion reduces crime stems from a 1966 Swedish study that compared the plight of the "unwanted" children of women who were denied abortions, with "wanted" children born at the same time. While there is no doubt that environment influences behavioral outcomes, Lott notes that the authors of the original report "never investigated whether the children's 'unwantedness' caused their problems, or were simply correlated with them."

This is a common deficiency in data interpretation. While two events may seem to be correlated, the appearance of connectedness does not necessarily imply causation. It is easy to correlate data, it is quite another thing to do the hard work of determining causation.

An example of this error that comes to my mind is an infamous one in which a Navy F-14 Tomcat crashed into the Pacific Ocean on approach to an aircraft carrier, killing its (equally infamous) pilot. The press (most notably Peter Jennings) droned on about the bad fortune of the deceased pilot whose plane had crashed "because of engine failure." Yes, the F-14's engine had failed. That fact was correlated with the crash of the airplane and the death of its pilot. But what the press (and the Navy) failed to mention was what the rest of us Naval Aviators knew -- the F-14 is a two-seat airplane. The backseater of that fateful event not only survived, but was eyewitness to, and knew exactly how, the airplane's engine had failed. As it turned out, the cause of the engine failure was a pilot-induced error. The pilot had stalled the engine herself and failed at the basic aviation procedures meant to correct for such an engine failure. While the engine failure could be correlated with the crash, the actual cause was the pilot herself.

Back to the issue at hand. The aforementioned study took on a life of its own and became the cornerstone of the "abortion decreases crime" theory which later studies assumed to be true in interpreting their own data. But a closer look at the demographics in the data shows that abortion could not have been the cause of the drop in crime rates in the early 1990s. As Lott points out:
... murder rates began falling first among an older generation -- those over 26 -- born before Roe. It was only later that criminality among those born after Roe began to decline. (emphasis mine)
Likewise, data from Canada shows that:
... while crime rates in both the United States and Canada began declining at the same time, the Canadian Supreme Court [did not strike] down limits on abortion nationwide until 1988.
Note to data "correlators": The "unwanted" criminals were 3 years-old when violent crime started its decline north of the border.

In fact, Lott shows that rates of out-of-wedlock births and single-parent families soared after Roe for many reasons that have been documented elsewhere. Both of these have been shown to be causal factors in the likelihood of later criminal behavior. So, a closer look at the data indicates not only that the "abortion-decreases crime" theory is false, but that its exact opposite has been shown to be true. Increases in abortion actually increase crime.

Serge and Jay have been masterful in demonstrating the devious advertising, data manipulation and outright falsehoods that have been perpetrated by pro-abortion advocates. Here we have yet another example of the data collectors, interpreters and reporters making the data say whatever they want it to say.

1 comment:

  1. I love this piece. You are absolutely right that it does not address the moral issue of abortion at all. I heard it discussed by Steven Dubner and Dennis Prager while Freakonomics was at its hottest and they talked about the correlation as if it were a proven causal relation. Prager continuosly asserted how obviously true this was to him.

    I guess I am certain that if we decreased the population to zero that we would see a reduction in violent crime. Of course that does leave out the thing that is so obvious to me. Violent reduction of the population is a crime against humanity whether the law protects it or not.


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