Thursday, January 03, 2008

Thrifty-gene hypothesis tested...brilliantly!

This is one of the best papers I've read in a while, not so much for the details of what they did, because I couldn't really follow all the economic jargon and models, but more for the overall concept. Every time I go to a buffet, all-you-can-eat style place (which is not often) I fantasize about doing research looking at optimal foraging theory in humans. I would want to see which people go for what foods (fat, protein, carbohydrates, vegetables, fruits, meat). I thought it would be fascinating to see what SES, biological, genetic, cultural factors determine how people decide on which foods to eat, or what they put place value on. I know that for me, for example, I find that my money would travel farthest if I take advantage of all the meat there is, but this can be seen as a very short term strategy, and probably the most optimal foraging strategy is to go for all the vegetables and fruit and "healthy stuff", even though I'd feel like I was "wasting" my money.
In this paper, the authors looked at purchases at nine grocery stores that are mainly frequented by Native Americans and nine grocery stores that are mainly frequented by Whites (or maybe just non-Native Americans) and looked at differences in purchasing behavior between them. They find that Native Americans do place a higher "dynamic shadow price" on protein, lending some support to the thrifty gene hypothesis. Now, I'm not saying this is water tight evidence or that there aren't issues with their analyses (or that I even understand everything they did), but I think their overall method is awesome.

Native American Obesity: An Economic Model of the "Thrifty Gene" Theory

Timothy J. Richards, Paul M. Patterson

American Journal of Agricultural Economics, August 2006, 88 (3), 542–560.
Abstract: Native American obesity is hypothesized to result from three potential causes: (1) a genetic predisposition, or the "thrifty gene," (2) a rational addiction to nutrients, and (3) dietary adjustment costs. These hypotheses are tested using a two-stage household production approach and scanner data from a panel of Native and non-Native supermarkets. Nutrient intake for both groups is strongly influenced by adjustment costs. Native Americans tend to place higher implicit valuations on protein relative to fats and carbohydrates compared to non-Natives. Consequently, reductions in real carbohydrate prices over time may be a cause of high incidence of Native American obesity.

1 comment:

Anonymous said...

Happy New Year !

Thanks for your blog. I'm a French Ph D. student in marketing and I find it 's an efficient way to get news from evolutionary research.

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