Legalized abortion and crime effect

The legalized abortion and crime effect is the controversial theory that legal abortion reduces crime. Proponents of the theory generally argue that "unwanted children" are more likely to become criminals and that an inverse correlation is observed between the availability of abortion and subsequent crime. In particular, it is argued that the legalization of abortion in the United States, largely due to the Supreme Court's decision in Roe v. Wade, has reduced crime in recent years. Opponents generally dispute these statistics, and point to negative effects of abortion on society.

Although others suggested this correlation in the past, the two academics most associated with this theory are Steven Levitt of the University of Chicago and John Donohue of Yale University with their 2001 paper "The Impact of Legalized Abortion on Crime".

Relation to controversy about legal abortion
Support for this theory is logically separate from support for legal abortion. Levitt suggests the following argument: suppose an individual assigns a low value to the life of a fetus, versus that of a newborn infant or adult, say 1 percent? However, there are only 15,000 murders in the whole of the United States in any given year. This is the total number of murders in the United States in any given year and is far more than the number of murders eliminated due to abortion. However there were millions of abortions during this same time. Therefore the "cost" of abortion was not paid in full by the reduction in murder (though one would expect to see a reduction in other crimes as well). Only if the value of the life of a fetus was very near zero in comparison to the value of an adult life would the "cost" of the abortions be paid for by the reduction in murders. Levitt also states that whereas the male contingent of aborted fetuses would have been prone to criminality, the female contingent would have been prone to unwed motherhood. Rates of unwed motherhood have increased, however, since the time of Roe v. Wade, not peaked and then significantly decreased, as is the case for the crime rates.

Levitt's theory has been claimed by former Secretary of Education William Bennett as the inspiration for his controversial - and widely denounced - statement that "if you wanted to reduce crime -- if that were your sole purpose, you could abort every black baby in this country, and your crime rate would go down." Levitt denies that his theory has racial implications.

Several commentators and professional economists have challenged Levitt's methodology and conclusions .

Some abortion opponents point out that arguments for abortion based on his theory are consequentialist in nature..

Donohue and Levitt's study
Donohue and Levitt use statistics to point to the fact that males aged 18 to 24 are most likely to commit crimes. Data indicate that crime started to decline in 1992. Donohue and Levitt suggest that the absence of unwanted aborted children, following legalization in 1973, led to a reduction in crime 18 years later, starting in 1992 and dropping sharply in 1995. These would have been the peak crime-committing years of the unborn children.

The authors argue that states that had abortion legalized earlier and more widespread should have the largest reductions in crime. Donohue and Levitt's study indicates that this indeed has happened: Alaska, California, Hawaii, New York, and Washington experienced steeper drops in crime, and had legalized abortion before Roe v. Wade. Further, states with a high abortion rate have experienced a greater reduction in crime, when corrected for factors like average income. Finally, studies in Canada and Australia have established a correlation between legalized abortion and crime reduction.

Criticisms

 * John Lott and John Whitley argue that Donohue and Levitt assume that states which completely legalized abortion had higher abortion rates than states where abortion was only legal under certain conditions (many states allowed abortion only under certain conditions prior to Roe) and that CDC statistics do not substantiate this claim. In addition, if abortion rates cause crime rates to fall, crime rates should start to fall among the youngest people first and then gradually be seen lowering the crime rate for older and older people. In fact, they argue, the murder rates first start to fall among the oldest criminals and then the next oldest criminals and so on until it last falls among the youngest individuals. Lott and Whitley argue that if Donohue and Levitt are right that 75 percent of the drop in murder rates during the 1990s is due solely to the legalization of abortion, their results should be seen in these graphs without anything being controlled for, and that in fact the opposite is true.


 * In 1999, before the paper was published, a debate was held between magazine writer and Internet columnist Steve Sailer and Steven Levitt at Slate.com. (See this link for Levitt's opening, this link for Sailer's response, this link for Levitt's rebuttal, and this link for a final Sailer response.) Sailer says that, contrary to what Levitt's thesis would suggest, "the murder rate for 1993's crop of 14- to 17-year-olds (who were born in the high-abortion years of 1975 to 1979) was a horrifying 3.6 times that of the kids who were 14 to 17 years old in 1984 (who were born in the pre-legalization years of 1966 to 1970)."


 * Since Donohue and Levitt used correlational statistics, causality can only be suggested. In other words, it is possible that another factor other than abortion (which would have to be negatively correlated with abortion rates at the time of a child's birth), caused all or some of decline in the crime rate. In November 2005, Federal Reserve Bank of Boston economists Christopher Foote and Christopher Goetz released a working paper, "Testing Economic Hypotheses with State-Level Data: A Comment on Donohue and Levitt (2001).", in which they argued that Donohue and Levitt's study did not estimate the regressions that Donohue and Levitt had claimed that they examined.  In particular, Foote and Goetz said that, despite their claims that they had done so, the 2001 Donohue and Levitt study failed to control for influences that varied within a state from year to year (such as the effect of crack-cocaine). Foote and Goetz also point out that Donohue and Levitt accidentally used the total number of arrests, not the arrest rate, to explain the murder rate. Using the total number of arrests does not establish the unwantedness mechanism Donohue and Levitt propose, only that the total number of arrests has changed. After making these two corrections, Foot and Goetz interpreted their results as evidence that violent crime actually increases with more abortions and that property crime is unrelated to abortions.  This study received press coverage in The Wall Street Journal and The Economist (link is here).

Donohue and Levitt admit the programming error made in the original version of the paper and then go on to address the two points that Foote and Goetz make (see here for the reply). Donohue and Levitt contend that even though Foote and Goetz analysis was doing what Donohue and Levitt claim that they were originally doing, the Foote and Goetz analysis produces heavy attenuation bias (the reason they find no statistical relationship between abortion and crime). To remedy this, Donohue and Levitt use the improved abortion measures (that Lott and Whitley originally used) and they make other changes that they now argue are necessary. Donohue and Levitt claim that with these new changes the results are smaller, but still statistically significant.


 * Ted Joyce made a number of arguments against the abortion and crime hypothesis in his 2004 paper "Did Legalized Abortion Lower Crime?" (Journal of Human Resources, 2004, VOL 39, No.1, pp. 1-28.). He claimed that legal abortions in the early 1970s were just replacing illegal abortions, that there was no measurable impact of abortion between 1985 and 1990, that cohorts born before 1973 had roughly the same crime rates as cohorts born after 1973 in the states where abortion was legalized in 1973, and that omitted variables are driving the results.

Donohue and Levitt respond to each point that Joyce makes in their paper "Further Evidence that Legalized Abortion Lowered Crime: A Reply to Joyce" (Journal of Human Resources, 2004, 39(1), pp. 29-49) and conclude that none of Joyce's arguments cast doubt on the original hypothesis presented in their 2001 paper. They also introduce an updated version of their dataset which had better measures of abortion (given to them by Stanley Henshaw of the Alan Guttmacher Institute after their initial paper was published).


 * John D. Mueller introduced a new argument into the debate in his review of Freakonomics, published in the Claremont Review of Books in Spring of 2006. He said that the Donohue and Levitt model had its "standard errors explode due to multicollinearity" when both contemporary and historic abortion rates were included in the statistical analysis.  Donohue and Levitt opted to exclude contemporary abortion rates from their analysis.  Mueller, on the other hand, posits that economic fatherhood is a prime determinant of violent crime; the reasoning being that supporting a child makes a man much less likely to commit a violent crime.  Economic fatherhood, as defined by Mueller, demonstrates a strong correlation with both crime and with abortion.  Such an analysis not only makes sense of abortion rates in the 1980s and 1990s, Mueller says, but also explains the rise in violent crime beginning in the late 1960s and continuing through the 1970s.

AEI conference
On March 28 2006, the American Enterprise Institute held a conference with Donohue, Lott, Foote, Joyce, and Leo Kahane presenting papers on the topic.

Other research

 * Charles, Kerwin Ko., and Melvin Stephens, Jr. 2002. "Abortion Legalization and Adolescent Substance Abuse." NBER Working paper No. 9193.
 * Leigh, Andrew, and Justin Wolfers, "Abortion and Crime," AQ: Journal of Contemporary Analysis 2000, 72(4), pp. 28-30.
 * Pop-Eleches, Christian. 2003. "The Impact of an Abortion Ban on Socio-Economic Outcomes of Children: Evidence from Romania." Harvard University Department of Economics. Unpublished.
 * Sen, Anindya. 2002. "Does Increased Abortion Lead to Lower Crime? Evaluating the Relationship between Crime, Abortion, and Fertility." University of Waterloo Department of Economics. Unpublished.
 * Sorenson, Susan, Douglas Wiebe, and Richard Berk, "Legalized Abortion and the Homicide of Young Children: An Empirical Investigation," Analyses of Social Issues and Public Policy 2002, 2(1), pp. 239-56.