# Levitt on Abortion/Crime: A FREAK-TV Collage of Evidence

### Video

In the video player on the left, you’ll find Part 2 of Levitt’s discussion of the research behind the abortion/crime link. (You can find Part 1 in the video player as well; here’s the blog post that accompanied it.) In this installment, he discusses the collage of evidence that convinced him and John Donohue of the link between legalized abortion and a lower crime rate.

### COMMENTS: 31

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1. Citizen Camillus says:

Looks like trouble for the abortion-crime argument from Prof’s Anderson and Wells:

http://papers.ssrn.com/sol3/papers.cfm?abstract_id=997912

Concepts of numerical analysis with applications to least squares problems are introduced in a manner which the practitioner can readily apply to their research problems, especially in the social sciences. Numerical analysis is mainly concerned with the accuracy and stability of numerical algorithms. We frame these concerns in terms of forward and backward error, two important concepts in helping to understand the quality of the computed answers. The goal of numerical computing is to get correct, approximate answers to the true solution. We extended this forward and backward error framework to issues in least squares problems and check the condition of the regression problem via condition numbers. The more ill-conditioned the data are, the more sensitive the computed solution is to perturbations in the data, and the more unstable the computed solutions become. Condition numbers can also be used to signal the presence of solution degrading collinearity in regression problems. We apply the various numerical analysis tools outlined with some model diagnostics to the abortion-crime debate, and show the regression analysis used in various papers addressing the abortion-crime debate cannot be trusted.

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2. Citizen Camillus says:

Looks like trouble for the abortion-crime argument from Prof’s Anderson and Wells:

http://papers.ssrn.com/sol3/papers.cfm?abstract_id=997912

Concepts of numerical analysis with applications to least squares problems are introduced in a manner which the practitioner can readily apply to their research problems, especially in the social sciences. Numerical analysis is mainly concerned with the accuracy and stability of numerical algorithms. We frame these concerns in terms of forward and backward error, two important concepts in helping to understand the quality of the computed answers. The goal of numerical computing is to get correct, approximate answers to the true solution. We extended this forward and backward error framework to issues in least squares problems and check the condition of the regression problem via condition numbers. The more ill-conditioned the data are, the more sensitive the computed solution is to perturbations in the data, and the more unstable the computed solutions become. Condition numbers can also be used to signal the presence of solution degrading collinearity in regression problems. We apply the various numerical analysis tools outlined with some model diagnostics to the abortion-crime debate, and show the regression analysis used in various papers addressing the abortion-crime debate cannot be trusted.

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3. David Kessler says:

TDK Wrote: “Actually Britain legalised abortion in the 1960s, 1967+/-2 I would guess. That would lead to a drop in 1995″

1967 is correct. But shouldn’t the crime drop be in 1985? By 1995 they’d be 28 – or rather NOT be, if they weren’t born! And as far as I know there was NO drop in crime in Britain in the mid 1980’s. So the legalization of (free) abortion doesn’t seem to have done anything to reduce crime in the UK.

As for leaded gasoline, I remember as a member of Friends of the Earth in the early seventies we were calling for it to be banned on the grounds of evidence (albeit inconclusive) that it caused hyperactivity in children – which could go on to lead to criminality.

Leaded gasoline (or leaded petrol as we call it here) was finally banned in the year 2000. So I guess we’ll have to wait till 2018 to see the results!

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4. David Kessler says:

TDK Wrote: “Actually Britain legalised abortion in the 1960s, 1967+/-2 I would guess. That would lead to a drop in 1995″

1967 is correct. But shouldn’t the crime drop be in 1985? By 1995 they’d be 28 – or rather NOT be, if they weren’t born! And as far as I know there was NO drop in crime in Britain in the mid 1980’s. So the legalization of (free) abortion doesn’t seem to have done anything to reduce crime in the UK.

As for leaded gasoline, I remember as a member of Friends of the Earth in the early seventies we were calling for it to be banned on the grounds of evidence (albeit inconclusive) that it caused hyperactivity in children – which could go on to lead to criminality.

Leaded gasoline (or leaded petrol as we call it here) was finally banned in the year 2000. So I guess we’ll have to wait till 2018 to see the results!

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5. Mary says:

I agree with the person who commented “It argues that if a person is statistically more likely … to commit a crime, we should kill them to prevent that crime.”

You could also argue that we should abort all the babies of the poor – we could pretty much eliminate povety that way, too. Is Mr. Dubner saying kill off our problems instead of looking for positive ways to solve them?
Even though his statistical methods in this case have been discounted Mr. Dubner is still pushing this idea.

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6. Mary says:

I agree with the person who commented “It argues that if a person is statistically more likely … to commit a crime, we should kill them to prevent that crime.”

You could also argue that we should abort all the babies of the poor – we could pretty much eliminate povety that way, too. Is Mr. Dubner saying kill off our problems instead of looking for positive ways to solve them?
Even though his statistical methods in this case have been discounted Mr. Dubner is still pushing this idea.

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7. Steven S.Baum says:

Sorry to burst a bubble,but the highest rate of crime comes from the LOWEST rate of abortions in our society = black & minority.
MOST criminals are from the lower income [ welfare ] part of society,and that points to abortion NOT being the cause of less crime in the past few decades.
I was a police officer and I dont mince words,or facts.
The facts speak for themselves,and that is not a “poll” that is taken by those with agendas.

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