Thursday, November 02, 2006

The worst mistake ever?

Of course, I went ahead and downloaded the new book by Gregory Clark. I have NOT read it- it is 453 pages long- but the opening passages are striking.

The basic outline of world economic history is surprisingly simple. Indeed it can be summarized in one diagram: figure 1.1. Before 1800 income per person – the food, clothing, heat, light, housing, and furnishings available per head - varied across societies and epochs. But there was no upward trend. A simple but powerful mechanism explained in this book, the Malthusian Trap, kept incomes within a range narrow by modern standards.

Thus the average inhabitant in the world of 1800 was no better off than the average person of 100,000 BC. Indeed, most likely, consumption per person declined as we approached 1800. The lucky denizens of wealthy societies such as eighteenth century England or the Netherlands managed a material life style equivalent to the Neolithic. But the vast swath of humanity in East and South Asia, particularly in Japan and in China, eked out a living in conditions that seem to have been significantly poorer than those of cavemen.

The quality of life quality also failed to improve on any other observable dimension. Life expectancy was the same in 1800 as for the original foragers of the African savannah, 30-35 years at birth. Stature, a measure both of the quality of the diet, and of children’s exposure to disease, was higher in the Neolithic than in 1800. And while foragers likely satisfied their material wants with small amounts of work, the modest comforts of the English in 1800 were purchased only through a life of unrelenting drudgery. Nor did the variety of their material consumption improve. The average forager had a diet, and a work life, much more varied than the typical English worker of 1800 even though the English table by them included such exotics as tea, pepper, and sugar.

Finally hunter-gatherer societies are egalitarian. Material consumption varies little across the members. In contrast great inequality was a pervasive feature of the agrarian economies that dominated the world of 1800. The riches of a few dwarfed the pinched allocation of the masses. Considering even the broadest definition of material life, the trend, if anything, was downward from the Stone Age to 1800. And for the poor of 1800, those who lived on unskilled wages alone, the hunter-gatherer life would have been a clear improvement. Some will object that material living conditions, even including life expectancy and work efforts, give little impression of the other dimensions by which life changed between the Neolithic and 1800: dimensions such as security, stability, and personal safety. But we shall see below that however broadly we picture living conditions, things do not improve before 1800.

This reminded me of the famous article in Discover, by Jared Diamond, arguing that we should never have invented Agriculture.

Scattered throughout the world, several dozen groups of so-called primitive people, like the Kalahari bushmen, continue to support themselves that way. It turns out that these people have plenty of leisure time, sleep a good deal, and work less hard than their farming neighbors. For instance, the average time devoted each week to obtaining food is only 12 to 19 hours for one group of
Bushmen, 14 hours or less for the Hadza nomads of Tanzania. One Bushman, when asked why he hadn’t emulated neighboring tribes by adopting agriculture, replied, "Why should we, when there are so many mongongo nuts in the world?"

While farmers concentrate on high-carbohydrate crops like rice and potatoes, the mix of wild plants and animals in the diets of surviving hunter-gatherers provides more protein and a bettter balance of other nutrients. In one study, the Bushmen’s average daily food intake (during a month when food was plentiful) was 2,140 calories and 93 grams of protein, considerably greater than the recommended daily allowance for people of their size. It’s almost inconceivable that Bushmen, who eat 75 or so wild plants, could die of starvation the way hundreds of thousands of Irish farmers and their families did during the potato famine of the 1840s.

There is evidence that adopting agriculture ruined the health of most people for generations

Skeletons from Greece and Turkey show that the average height of hunger-gatherers toward the end of the ice ages was a generous 5’ 9" for men, 5’ 5" for women. With the adoption of agriculture, height crashed, and by 3000 B. C. had reached a low of only 5’ 3" for men, 5’ for women. By classical times heights were very slowly on the rise again, but modern Greeks and Turks have still not regained the average height of their distant ancestors.


At Dickson Mounds, located near the confluence of the Spoon and Illinois rivers, archaeologists have excavated some 800 skeletons that paint a picture of the health changes that occurred when a hunter-gatherer culture gave way to intensive maize farming around A. D. 1150. Studies by George Armelagos and his colleagues then at the University of Massachusetts show these early farmers paid a price for their new-found livelihood. Compared to the hunter-gatherers who preceded them, the farmers had a nearly 50 per cent increase in enamel defects indicative of malnutrition, a fourfold increase in iron-deficiency anemia (evidenced bya bone condition called porotic hyperostosis), a theefold rise in bone lesions reflecting infectious disease in general, and an increase in degenerative conditions of the spine, probably reflecting a lot of hard physical labor. "Life expectancy at birth in the pre-agricultural community was bout twenty-six years," says Armelagos, "but in the post-agricultural community it was nineteen years. So these episodes of nutritional stress and infectious disease were seriously affecting their ability to survive."

Why was agriculture so bad for human health?

There are at least three sets of reasons to explain the findings that agriculture was bad for health.

First, hunter-gatherers enjoyed a varied diet, while early farmers obtained most of their food from one or a few starchy crops. The farmers gained cheap calories at the cost of poor nutrition. (today just three high-carbohydrate plants–wheat, rice, and corn–provide the bulk of the calories consumed by the human species, yet each one is deficient in certain vitamins or amino acids essential to life.) Second, because of dependence on a limited number of crops, farmers ran the risk of starvation if one crop failed. Finally, the mere fact that agriculture encouraged people to clump together in crowded societies, many of which then carried on trade with other crowded societies, led to the spread of parasites and infectious disease. (Some archaeologists think it was the crowding, rather than agriculture, that promoted disease, but this is a chicken-and-egg argument, because crowding encourages agriculture and vice versa.)

Epidemics couldn’t take hold when populations were scattered in small bands that constantly shifted camp. Tuberculosis and diarrheal disease had to await the rise of farming, measles and bubonic plague the appearnce of large cities.

and things get worse

Besides malnutrition, starvation, and epidemic diseases, farming helped bring another curse upon humanity: deep class divisions. Hunter-gatherers have little or no stored food, and no concentrated food sources, like an orchard or a herd of cows: they live off the wild plants and animals they obtain each day. Therefore, there can be no kings, no class of social parasites who grow fat on food seized from others. Only in a farming population could a healthy, non-producing élite set itself above the disease-ridden masses. Skeletons from Greek tombs at Mycenae c. 1500 B. C. suggest that royals enjoyed a better diet than commoners, since the royal skeletons were two or three inches taller and had better teeth (on the average, one instead of six cavities or missing teeth). Among Chilean mummies from c. A. D. 1000, the élite were distinguished not only by ornaments and gold hair clips but also by a fourfold lower rate of bone lesions caused by disease.

Farming may have been even worse for women

Farming may have encouraged inequality between the sexes, as well. Freed from the need to transport their babies during a nomadic existence, and under pressure to produce more hands to till the fields, farming women tended to have more frequent pregnancies than their hunter-gatherer counterparts–with consequent drains on their health. Among the Chilean mummies for example, more women than men had bone lesions from infectious disease.

Women in agricultural societies were sometimes made beasts of burden. In New Guinea farming communities today I often see women staggering under loads of vegetables and firewood while the men walk empty-handed. Once while on a field trip there studying birds, I offered to pay some villagers to carry supplies from an airstrip to my mountain camp. The heaviest item was a 110-pound bag of rice, which I lashed to a pole and assigned to a team of four men to shoulder together. When I eventually caught up with the villagers, the men were carrying light loads, while one small woman weighing less than the bag of rice was bent under it, supporting its weight by a cord across her temples.

So why did our silly ancestors take up agriculture at all? The proposed explanation seems to be based on a kind of group selection.

One answer boils down to the adage "Might makes right." Farming could support many more people than hunting, albeit with a poorer quality of life. (Population densities of hunter-gatherers are rarely over on eperson per ten square miles, while farmers average 100 times that.) Partly, this is because a field planted entirely in edible crops lets one feed far more mouths than a forest with scattered edible plants. Partly, too, it’s because nomadic hunter-gatherers have to keep their children spaced at four-year intervals by infanticide and other means, since a mother must carry her toddler until it’s old enough to keep up with the adults. Because farm women don’t have that burden, they can and often do bear a child every two years.

As population densities of hunter-gatherers slowly rose at the end of the ice ages, bands had to choose between feeding more mouths by taking the first steps toward agriculture, or else finding ways to limit growth. Some bands chose the former solution, unable to anticipate the evils of farming, and seduced by the transient abundance they enjoyed until population growth caught up with increased food production. Such bands outbred and then drove off or killed the bands that chose to remain hunter-gatherers, because a hundred malnourished farmers can still outfight one healthy hunter. It’s not that hunter-gatherers abandonded their life style, but that those sensible enough not to abandon it were forced out of all areas except the ones farmers didn’t want.

I am much more optimistic about the future than Diamond is in this article. He seems to expect the return of what Gregory Clark calls the Malthusian Trap. I suspect that no wwe know the trick of getting out of that trap, we are unlikely to go back there.


gaddeswarup said...

I too am browsing through Clark's book and find some of it Cowen's comments strange; they do not seem to take in to account democracy v colonialism, nutrition, weather etc in to account. And as Abi of nanopolitan says, what about incentives. Abi also refers to the following discussion (Thoma):

gaddeswarup said...

Pl. check "Institutions as the Fundamental Cause of Long-Run Growth" by D.Acemoglu, S.Johnson, J.Robinson avaiable at Acemoglu's site. I do not know much about these topics and am trying to learn. I find Acemoglu's papers interesting. Would like to see your reactions to them. Regards,

Rajeev Ramachandran said...

Hi Swarup
Am visiting Chennai, with VERY limited access to the net. Shall resume blogging when I return to Mumbai. Acemoglu is always interesting, but I suspect this is like a huge puzzle of which we are able to grasp only small pieces. Cheers. :-)