October 11, 2012

Advice for economists contemplating incorporating genetic information in their theories

In the wake of the latest brouhaha with anthropologists denouncing two economists for daring to correlate "genetic diversity" with wealth in 145 countries, allow me to make a suggestion for economists interested in dipping their toes into studying the impact of genetic differences on economic phenomena: 

Start small. 

Don’t go for a Theory of Everything right away. Instead, look for a well-understood example of genetic differences and see how that plays out in the economic sphere, such as, say, the impact of altitude tolerance on real estate prices.

There are a handful of well-established, uncontroversial cases of simple gene variants helping individuals adjust to a particular environment. For example, the Duffy allele fights vivax malaria and the famous sickle cell mutation fights the worst form of malaria, falciparum.

Similarly, Cynthia Beall and colleagues have identified separate mutations in Tibet and Bolivia-Peru that make life at very high altitudes more endurable. (There appear to be other adaptations in Ethiopia, but they hadn’t yet been pinned down the last time I check.)

The various lactose tolerance mutations have huge economic effects. The population density of northern Europe, such as Denmark and Ireland, before the industrial revolution would have lagged substantially without this mutation that supported a dairy-centric economy.

These noncontroversial genetic differences have obvious effects on quantifiable measures such as who lives where and how much the land they live on costs. For example, the Beijing government has been trying to swarm Tibet with loyal Han colonists, but lowland Chinese have problems adjusting to the lack of oxygen. I would predict that real estate prices in Tibet, all else being equal, would be highest in the deepest valleys and canyons, just as they are in La Paz, Bolivia, where the whitest people live at bottom of the canyon.

In Nepal, the Tibetan population (e.g., the famous mountaineering Sherpas) doesn’t like to live below about a mile high because they lack some of malaria resistance that the Indian population enjoys. The Indians, in turn, don’t like to get too high because they don't handle thin air as well as the Tibetans.

In Colorado, resort towns at around 8000 feet like Aspen and Vail are vastly expensive because they appeal to energetic, aerobically fit rich white people. But Leadville, a couple of thousand feet higher at 10,152 feet, remains something of a curiosity due to its extreme altitude, which is definitely pushing the envelope for whites, so land prices are lower.

A study of altitude tolerance in different populations would be relevant to say, real estate developers. Is a retirement community at 9000 feet a good idea, or does altitude tolerance drop off with age? How about 7000 feet? 5000 feet? This is a serious issue: my uncle spent 20 years building his retirement dream house at 8,900 feet in his beloved Sierra Nevadas, only to discover that he and his wife couldn't tolerate altitude as well anymore once they reached retirement age. (There are also big problems for pregnant women at extreme altitudes.)

Does the growing Mexican-American community of the Rocky Mountain States, many of whom are migrants from fairly high altitude parts of Mexico, have better or worse altitude tolerance than whites? 

You might be able to score some speakers fees at real estate conventions just by assembling all the relevant information on altitude tolerance.

There are a host of interesting implications, large and small, that might be uncovered by an exploration of the interplay of altitude (and/or latitude), genes, and economics.

15 comments:

David said...

But the NYT says the world is flat.

You altitudist.

DirkY said...

"The population density of northern Europe ... would have lagged substantially without this mutation that supported a dairy-centric economy."

The plague and constant wars kept population down more than lack of food production capacity. Mass starvation from crop failures etc is commonly recorded in Chinese history, as well as the more unified and densely populated France.

But Germany especially was in constant wars involving one sub-state of the Holy Roman Empire fighting another, usually with the support of differing foregin powers, who sent in troops who "lived off the land" by eating all the grain and livestock, and torturing the peasents to reveal any hidden stashes.

The worst-affected parts of modern Germany, Austria, and the Czech Republican lost 75% of their pre-war population during the hundreds of years of religious wars, which began in Luther's lifetime and only really ended after Napoleon more than 250 years later. The other all depopulation over the whole area was about 50%.

The Scandavanian states were also in an near-constant state of war, conquest, and rebellion with each other over the same period.

DirkY said...

I spent a few weeks in a city at 8000ft and a few days at one at 9200ft, and I didn't have an issue with the altitude, and I am not especially "energetic, aerobically fit." In fact I did not notice any difference compared to sea level.

I guess it never hurts to flatter people who vacation in Aspen!

Anonymous said...

"You altitudist."

LOL. Yes, Steve is the equivalent of an anti-dentite.

DirkY said...

Pleasent, fertile, and temperate central Mexico was constantly invaded by nomads from the deserts to the north, so the people who envolved there constantly received shots of lowland DNA.

For the same reasons it was where most of the Spanish settled, so it is one of the whiter parts of the country. The most Indian are the low-lying coastal areas.

So no, I don't think the average mestizo Mexican has great altitude adaptions.

Anonymous said...

"I spent a few weeks in a city at 8000ft and a few days at one at 9200ft, and I didn't have an issue with the altitude, and I am not especially "energetic, aerobically fit." In fact I did not notice any difference compared to sea level."

If you're relatively young and haven't been a smoker and you didn't do a lot of walking, hiking, biking, running,swimming, you wouldn't see the difference.

Anonymous said...

The worst-affected parts of modern Germany, Austria, and the Czech Republican lost 75% of their pre-war population during the hundreds of years of religious wars, which began in Luther's lifetime and only really ended after Napoleon more than 250 years later. The other all depopulation over the whole area was about 50%.

The Scandavanian (sic) states were also in an near-constant state of war, conquest, and rebellion with each other over the same period.


You have to wonder whether maybe this strife was a Darwinian mechanism of adaptation to emerging modernity.

This seems similar to the sort of degradation/high mortality/strife/plundering seen in areas of modern nations with a high density of demographics with a relatively short history of exposure to modernity.


Anonymous said...

http://www.nytimes.com/2012/10/12/opinion/global/chinas-leftover-women.html?smid=tw-share

If you get past the sneering tone of the article, the ideas the Chinese are pushing sound very sensible for improving the 'quality' of their population.

Anonymous said...

Blood absorption of oxygen falls off exponentially with altitude. I once calculated the half-hemoglobin-saturation altitude to be 3500 meters.

Anecdote: My grandfather retired in Colorado at 5000ft or so. Due to his emphysema, he required a supplemental supply of pure oxygen from tank. At a point when we began to worry that he wouldn't last much longer, he visited my Aunt in Kansas, where he didn't need the Oxygen at all. Soon after he moved there and ended up living another 15 years.

Anonymous said...

Perhaps they can pay you for shutting up, or if writing is something you can't do without, have a private newsletter where they laugh themselves silly.

jody said...

prices for leadville are (much) lower because it is an abandoned mining ghost town and nobody lives there. a couple hundred people. i go there once a year to help my friend on his run of the leadville 100. our base of operations is a condo in vail, where thouands of rich yuppies have their ski homes.

come on, steve.

by the way, the guy who organized the leadville 100 races is not from leadville or colorado or anywhere near there. he's a southerner who moved to leadville at random and decided he wanted to organize something that would put leadville back on the map. hence the 100. he even got lance armstrong to come race the mountain bike version of the race more than once.

personally i never have trouble operating at 12,000 feet, which is the highest elevations for parts of the leadville run, but some people can't handle that after a few days and get altitude sickness. but there are no big towns that high. denver is at 5000 and colorado springs is at 7000 and those are definitely not high enough to deter people.

CJ said...

I read that NYT article on the "leftover women" in China. It seems almost surreal to read something so commonsensical and accurate coming out of a government agency. BTW, the same concerns about educated women not having enough children have been expressed by Singapore's politicians.

The NYT writer quotes the All-China Women’s Federation material rather extensively. It reminded me of the former East European method of transmitting forbidden thoughts by quoting evil capitalists at length while ritually denouncing them about once per page. My favorite:

"When holding out for a man, if you say he must be rich and brilliant, romantic and hardworking ... this is just being willful. Does this kind of perfect man exist? Maybe he does exist, but why on earth would he want to marry you?"

Anonymous said...

I'm having trouble imagining how this study would go. You could do a study of how altitude impacts real estate prices, but no one is going to want to read that. Other academics wouldn't be interested because the statistical techniques you'd use are totally standard, and academics are going to want to see something a little bit fancy and novel. And real estate people wouldn't be interested because your study was done on whatever data you could get cheap from public sources, whereas they can have their in house economist whip something up from their proprietary data that will be much more accurate. (This is, by the way, why the academic people expect to see some fancy statistical technique. They see their role as developing new techniques which the second stringers who end up in industry with access to serious data can then apply.)

If you try to model the genetic factor explicitly, you're probably going to get "Poor indigenous group is concentrated on cheap land no one else wants", and you don't need any kind of altitude effect to explain that one.

Now if you had a situation where say a lot of rich Mexicans of indigenous descent were immigrating to Colorado and completely transforming the market for high altitude land, that would make a good study. You could show how the low altitude premium disappears over time. But you can't get the data until it actually happens.

pat said...

Recent expert testimony has attested to the fact that a mere altitude of 5,000 feet can adversely affect your debate performance.

Albertosaurus

Hapalong Cassidy said...

Here's a topic I've given some thought to recently: the susceptibility, or lack thereof, of different populations to alcoholism. Much ado has been made about how Native Americans are more susceptible to alcoholism. But I'm much more interested in the differences in Southern and Northern Europeans. It is my hypothesis that the slightly higher IQ of the more cold adapted Northern Europeans, was offset by their susceptibility to alcoholism. This is why it took so long for Germanic civilization to catch up to the Greeks and Romans. Alcohol would have been introduced to the Northern Europeans by the Greeks and Romans, and the Northern tribes' inability to tolerate alcohol kept them from organizing and challenging the Romans for supremacy. It took several centuries for the genetic mutation that confers resistance to alcoholism to spread throughout Northern European populations.