People don't move around that much, especially not in the first few years of their life.

What you're missing is that most chemical damage to infants is done in-utero, at their most vulnerable time (why you don't drink when pregnant).

No, I explicitly accounted for that, which is why I mentioned that measuring the rate of autism (which is measured as the number of people diagnosed with autism in a region) might not line up with exposure during pregnancy (which could have occurred in a different region entirely, especially if the autism diagnosis lags behind the birth)

What are you talking about? Region and location has nothing to do with this study.

They took the serum of the pregnant mother, measured that for the pesticide, and found it was a statistically significant predictor of autism.

The whole thread is responding to my suggestion that you ought to also find a geographical relationship between DDT application and autism.

Oh, shit, you're right. I didn't read your part not-in-italics.

Well, I suck. I was rude and incorrect. Thank you for taking the time to keep me humble.

Perhaps you could discount the results based on county or state migration records?

Although it seems plausible some families might move to places with better care which might affect how you weight your values.