Monday, December 29, 2008

Criticism of my pledge study

A blogger called Outside the Beltway writes about the validity of the study, and unleashes an intelligent barrage of comments from his readers about the methodology because he assumed I was doing standard regression analysis instead of matching. It's amazing how many methodological details people are able to pull from the media reports, and it's neat to see a political argument turn into a discussion of internal validity. I'm curious whether the phrase "parametric assumptions" will appear.

A few people --- Investors Business Daily and Valerie Huber cited at the end of the Post article --- have made accusations of ideological bias, which is a particularly ridiculous accusation to make about a statistician. If studies were determined by ideological bias, statistics would suddenly become much easier, and entire subfields of statistics such as procedures to adjust for multiple comparisons could disappear.

Ideological bias is also funny to raise about me, in particular. I vote straight blue and am firmly pro-choice, but I'm also frustratingly moderate. In discussions with reproductive health researchers, I stick up for the abstinence folks whenever it's warranted, and I read evangelical sex and dating books to the point that I know these better than some evangelical clergy, and I've even recommended evangelical dating books to friends.

The IBD editorial is particularly funny because it refers to the "fat wallet" of Mayor Bloomberg as having financed my study, which was not financed at all beyond the grants that paid for my PhD education, and then it links my study to the psilocybin study at Bayview, and repeats the same fallacy correlating teen pregnancy decline with rise of abstinence-only education.

They do get in a good line, "Abstinence-ed can't work as a one-night stand."

4 comments:

Anonymous said...

I was trying for the life of me to figure out what Michael Bloomberg had to do with your study. Didn't even think that endowing the Hopkins School of Public Health made him responsible for the results of your work, which sounds like it wasn't even conducted at Hopkins.

Andrew G. Biggs said...

I've not been able to find the paper online, so here's a question: is your finding that teens who take the pledge have the same sexual activity as kids who don't, or that, after controlling for other factors, the pledge doesn't predict sexual activity (i.e., the regression coefficient falls away)? I can easily believe the latter, since it may be that the pledge is an indicator of the kid's other attributes rather than a cause of his/her activity. That said, I think some of the press portrays these things in a way that folks might not totally understand.

Ronp said...

A quick read of Chapter 5 (The Influence of Arousal) in MIT behavioral economist Dan Ariely's new book "Predictably Irrational" illustrates how teenagers (in particular male college students) predictably behave irrationally when sexually aroused. He suggests that our policies of social normalization are wrongly targeted towards the unaroused instead of the aroused person (ala Jekel and Hyde).

Refs:
http://www.predictablyirrational.com/?page_id=218
http://www.predictablyirrational.com/pdfs/Heat_of_Moment.pdf

Anonymous said...

I believe that your study is biased and does not take into account the religious aspect of abstinence. There are so many teens that have taken and lived by the purity pledge. perhaps they just don't see the need to be involved in your "study".