The Escape from Hunger is an important book by the Nobel economist Robert Fogel. The first three chapters offer a novel, tightly constructed, and convincing argument for a distinctively human form of what Fogel calls “technophysio evolution,” described as “biological but not genetic, rapid, culturally transmitted, and not necessarily stable.” At first blush, biological evolution that is not genetic may sound surprising, but it rests on firm and quantitative evidence, as he explains:
The theory of technophysio evolution rests on the proposition that during the past 300 years, particularly during the past century, human beings have gained an unprecedented degree of control over their environment…. This new degree of control has enabled Homo sapiens to increase its average body size by over 50 percent and its average longevity by more than 100 percent since 1800, and to greatly improve the robustness and capacity of vital organ systems.
The two concluding chapters of the book are also surprising and boldly speculative since Fogel devotes them to an assessment of prospects for further technophysio evolution across the next hundred years, and explores the economic and social implications of making health care “the growth industry of the twenty-first century.”
No one can deny that the human record in the twentieth century was indeed extraordinary. For in spite of all the wars, massacres, and famines that figure in the conventional history of that century, human numbers quadrupled, and most people consumed more and suffered less deprivation than before. This is what Fogel undertakes to demonstrate statistically by applying an economist’s habits of mind to recent biological, physiological, and thermodynamic transformations of the human work engine, our bodies. This ambitious enterprise deserves both admiration and careful scrutiny.
As he tells us in the preface, the first part of this book is “based on the McArthur lectures that I delivered at Cambridge University in November 1996,” adjusted to a more popular audience by omitting some “highly technical” discussion. Behind those lectures stand more than forty years of investigation of changes in patterns of births, marriages, and deaths, drawn largely from English parish records of past centuries, undertaken by Sir Tony Wrigley and his colleagues at Cambridge University, and Fogel’s own thirty years of work, together with a team of assistants, studying changes in adult heights and weights derived mainly from European and American army records dating back to the eighteenth century. Wrigley died before Fogel could deliver the McArthur Lectures at Cambridge, but his junior colleague, Roderick Floud, carries on his work, and the full fruit of these efforts, supplemented by those of various French, Swedish, and Norwegian demographers, is announced in this short book’s bibliography as “Fogel, R.W., Floud, R., and Harris, B. (n.d.), A treatise on technophysio evolution and consumption. In progress.” As his footnotes attest, much crucial data for Fogel’s argument here is borrowed from that prospective work, so that what we have is a condensed, simplified, and preliminary version of the full argument.
Nonetheless, some aspects of the work in hand are beyond me. In particular, in 1982 one of Fogel’s associates at the University of Chicago generated a “three-dimensional diagram, called a ‘Waa- ler surface,’” that “illustrates how height and weight are related to the risk of both poor health and mortality.” Surely, risk of poor health is hard to quantify, yet Fogel clearly sets great store on this diagram. It appears as the frontispiece, is repeated in subsequent pages, and an appendix summarizes its mathematical genesis at the back. I must confess that I found both the language and the equations of this appen-dix largely unintellig-ible. Using data generated by two rounds of “polynomial interpolation” and rejecting results from a further round of inter- polation because of “added computational costs” may be persuasive to statisticians, even if, or especially when, the initial equation includes a factor for “random disturbance.” What makes some data random, pray tell? This mysterious factor, which I think must be arbitrary, perhaps makes every curve satisfactorily smooth. But generating data to make results come out as Fogel wants them strikes me as a dubious exercise of mathematical ingenuity. Consequently, I accepted the Waaler diagrams that appear throughout the first half of the book as an act of faith rather than the self-evident demonstration that Fogel perhaps expected his readers to admire.
Yet mathematical sleight of hand or no, I was thoroughly convinced by Fogel’s argument that chronic undernourishment among European and American populations prevailed in the eighteenth and nineteenth centuries, and presumably also prevailed throughout the rest of the world and across earlier centuries and millennia as well. This seems plausible to me partly because I am just old enough to have experienced dietary deprivation myself. Fresh fruit and vegetables disappeared from my mother’s kitchen in winter, and her nineteenth-century idea that cleanliness was supremely important for health intensified resulting vitamin shortages. For though we ate potatoes almost every day, their skins were thought to be dirty, so we threw away the limited supply of vitamins they contained. Accordingly, by springtime my body was well and truly short of vitamins.
Here is how I responded. When I was six or seven years old, as snow melt bared the ground, our Toronto back yard turned muddy. Cleanliness required me to wear rubbers when playing outside; and to take them off before entering the house again. One day when taking off my rubbers, I dirtied my fingers and sucked them clean, only to discover how delicious the mud tasted. Whereupon I scraped some larger blobs from my rubbers and ate them eagerly. I remember the taste—not sweet, not sour, not much of anything, and unpleasantly gritty though it was—as the most irresistible encounter my tongue ever had; and my subsequent deceit strengthened and confirmed the memory. For when my mother saw me eating mud on the doorstep that first time, she was horrified and strenuously forbade it. But I knew a good thing when I had once tasted it, and for the next few weeks I continued to eat mud from my rubbers surreptitiously until our yard dried out and the mud disappeared.
I now realize that my taste buds were reacting to vitamins in microorganisms that had begun to multiply in the mud. Eating them satisfied a deep-seated bodily craving and surely benefited me. But within a year—probably in 1925—newly discovered vitamins came to my mother’s attention and she started administering bad-tasting cod-liver oil to her children in wintertime, whereupon mud disappeared from my springtime diet.
The memory of this experience predisposes me to accept Fogel’s claim that malnourishment in childhood was once common and can be detected by the way it diminished adult height and weight. His further proposition that food deprivation in infancy reduced longevity and weakened adult resistance to infectious and chronic disease is plausible too, even if his statistical demonstration of that linkage through Waaler surfaces remains inaccessible to my mathematically undernourished mind.
To measure bodily undernourishment, Fogel relies on statistical methods pioneered in France after 1970 that compiled “agricultural accounts.” These, he tells us,
could be converted into estimates of the output of calories and other nutrients available for human consumption through a technique called “National Food Balance Sheets.” Such estimates are currently available for France more or less by decade from 1785 down to the present. In Great Britain, …estimates of the supply of food are now available by half cen-tury from 1700 to 1850 and by decade for much of the twentieth century.
He does not explain how these food balance sheets were compiled and I don’t suppose they can detect vitamin deficiencies of the sort that affected me, but in a rough-and-ready way they allow Fogel to estimate average nationwide access to calories; and calories can then be converted into energy flows within human bodies. Fogel never mentions margins of error, which must be significant for such calculations, perhaps reserving such technicalities for the forthcoming work. Instead he briskly lists some surprising conclusions from his thermodynamic calculations.
First, before about 1890 “even prime-age males had only a meager amount of energy available for work.” The rest went to maintenance of bodily functions—heartbeat, breathing, digestion, etc. Further, “variations in body size were a principal means of adjusting the population to variations in the food supply.” And most surprising of all:
It is worth noting that during the 1880s Americans were slightly shorter than either the English or the Swedes, but a century earlier the Americans had had a height advantage of 5 to 6 cm over both groups. This conflict between vigorous economic growth and very limited improvements or reversals in the nutritional status and health of the majority of the population suggests that the modernization of the nineteenth century was a mixed blessing for those who lived through it.
Fogel’s second chapter, “Why the Twentieth Century Was So Remarkable,” is the core of his book. He deploys Waaler surfaces to demonstrate the relationship between body size and risk of death, and for predicting the onset of chronic diseases. He sums things up as follows:
What is the basis for the predictive capacity of Waaler surfaces and curves?… Research in this area is developing rapidly, and some of the new findings have yet to be confirmed. The exact mechanisms by which malnutrition and trauma in utero or in early childhood are transformed into organ dysfunctions are still unclear. What is agreed upon is that the basic structure of most organs is laid down early, and it is reasonable to infer that poorly developed organs may break down earlier than well-developed ones. The principal evidence so far is statistical and…there is no generally accepted theory of cellular aging.
With this quantitative evidence for increased body size and improved health in hand, Fogel next asks what these physiological changes did to economic productivity. His conclusion is novel indeed:
The available data suggest that the average efficiency of the human engine in Britain increased by about 53 percent between 1790 and 1980. The combined effect of the increase in dietary energy available for work, and of the increased human efficiency in transforming dietary energy into work output, appears to account for about 50 percent of the British economic growth since 1790.
In short, the familiar basis of the Industrial Revolution in Great Britain—the deployment of new machines activated by inanimate forms of energy—was about evenly matched by increases in human capacity for work, thanks to better diet and resulting changes in bodily metabolism, health, and longevity.
Fogel next examines instances in which his new biomedical data conflict with older measures of per capita income and real wages. He concludes that because of “the unmeasured cost of mortality,” which increased as the United States became more urban, “much of what appears to have been a rise in real wages between 1790 and 1860 is spurious.” Similarly, in Great Britain “disparity between the upper and lower classes increased during much if not most of the nineteenth century,” whereas calculations of income distribution indicate no such divergence.