Tuesday, February 27, 2007

Wall Street Journal Questions Economist's "TV Causes Autism" Theory

Economics is hot. Two correlated data points support this observation:

1. "Freakonomics," by Steven D. Levitt and Stephen J. Dubner, in which "a maverick scholar and a journalist apply economic theory to everything from cheating sumo wrestlers to abortion and the falling crime rate," has been on The New York Times bestseller list (hardcover non-fiction) for 93 weeks.

2. The Wall Street Journal today published a page-one article about the work of another maverick economist, Michael Waldman of Cornell University, who has posited that too much TV watching can cause autism in young children. See the article "Is an Economist Qualified to Solve Puzzle of Autism?" here for a limited time (The Journal is subscription only).

In the article, reporter Mark Whitehouse uses Waldman's controversial paper as a way to analyze a research technique in economics called the instrumental variable, "a statistical method that, by introducing some random or natural influence, helps economists sort out questions of cause and effect." This research method, the article explains, allows economists to create experiments "that seek to approximate the rigor of randomized trials -- the traditional gold standard of medical research."

Some very interesting theories arise from this research method. For example: if you were drafted to serve in Vietnam, you were likely to earn less than other men who weren't; additional police hired in big cities reduce crime (a study by "Freakonomics" author Levitt); greater competition among school districts leads to better academic results. The Journal article cites all of these studies, and more, by esteemed economists over the past 17 years.

The problem with Waldman's study-- which said, basically that where it rains more, kids watch more TV; and where it rains more and more kids watch TV, there is more incidence of autism cases -- is that it doesn't appear likely to hold up to much scrutiny. As Whitehouse reports, more precipitation could be linked to household mold; does that cause more autism?

Back in October, when Professor Waldman posted his unpublished research study "Does Television Cause Autism?" it got a lot of press-- and as The Journal notes, created quite a bit of angst among parents of children with autism spectrum disorders who were prompted to ask if their struggles with developmentally disabled kids were their own fault. (You can read an Autism Bulletin article, with more information and a link to the study, by clicking here.)

If you have the time, read The Journal article not just because it's well done and interesting, but because the TV-causes-autism theory has some stamina. A Harvard economist plans to test Waldman's results. Your friends or relatives may bring it up.

We have seen time and again how parents of kids with autism spectrum disorders do amazing things -- start a support services center, write groundbreaking books, take their right to defend their children to the Supreme Court, lobby Congress to pass new legislation, fight for society's acceptance. In this context, you won't be surprised to find another correlation: Professor Waldman got interested in studying autism from his personal experience.

His young son was diagnosed with ASD. He later improved so much to qualify as "fully recovered," after a regime that included recommended therapies and a sharp reduction in television time. This led to his research questions, his publicizing a research paper, and his recommendation that parents of young children limit their tots' time in front of the tube.

If only life were that simple.


Susan Senator said...

It is nothing less than sophistry. It's been going on since the beginning of time.

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