Conquests and Cultures: An International History.

• Author: Mokyr, Joel

by Thomas Sowell, New York: Basic Books, 493 pages, $35.00

Global economic history is "in" again. Along with the two books reviewed here, I could mention David Landes's The Wealth and Poverty of Nations, Richard Easterlin's Growth Triumphant, Robert McC. Adams's Paths of Fire, and Patrick Verley's L'echelle du Monde. More are on the way. All of these books are trying, in one way or another, to answer the question posed by Thomas Sowell: Why does 17 percent of the world produce four-fifths of its output? A more elegant way of raising the same issue is what Jared Diamond calls "Yali's question." Yali is a New Guinea notable who one day asks Diamond why white people have so much "cargo" - Western manufactured goods desired by New Guineans - while New Guinea produces no cargo of interest to Westerners.

Everyone understands that these questions can never be answered in a definitive way, comparable to proving Fermat's Last Theorem. The distribution of prosperity is hopelessly "overdetermined": There are far too many answers that all seem to be right. Culture, geography, institutions, war, religion, and even historical accidents all seem to have played a role. But what role, and which factors are most important, remain matters of controversy.

Thomas Sowell's Conquests and Cultures is the third volume of a trilogy, preceded by Race and Culture and Migrations and Cultures. Sowell, a noted economist and social commentator at Stanford's Hoover Institution, raises the interesting issue of what happens when two culturally and economically different societies clash militarily and one of them "conquers" the other. Using this general framework, he analyzes four historical cases in which conquest played a major role: England, Africa, the Slavic people, and the Western Hemisphere Indians. These chapters show that conquests do not have much in common, yielding a somewhat confused picture. In Africa, conquest led to slavery for a large proportion of the population; in the Western Hemisphere, to the physical destruction of much of the indigenous population; in Eastern Europe, where conquerors and conquered changed positions over time, to an unstable and variable clash of cultures.

Conquests come in many forms, from the long-term occupations of the Romans in the Mediterranean to the short-lived mega-empires of Tamerlane. Some of them led to a forced or voluntary assimilation of the conquered to the language and customs of the victors, but in other cases the reverse occurred (for example, the Roman conquest of Greece or the Mongol conquests of China). Sowell points out that being conquered often led to a long-term increase in living standards and economic performance, and in some cases when the occupiers withdrew (as the Romans did from Britain in the fifth century) the occupied countries sank into poverty and barbarism. In Sowell's view, exploitation and theft do not go nearly as far in explaining economic differences as culturally caused differences in productivity.

The key concept in Sowell's view of history is "cultural capital," which is transferred and diffused among societies. The concept is nowhere defined with any precision, and at times it seems to be interchangeable with "human capital," though Sowell uses that term rather loosely as well, often more in the sense of mentalite and social institutions than in the sense employed by economists (an economically useful formal education). Yet his overall view of history is quite clear: People are born with very similar innate abilities, but their economic achievements differ enormously due to differences in "cultural capital," which determines not only such matters as technological sophistication but also "attitudes" such as diligence, honesty, and ambition. For Sowell, the most important form of cultural capital is freedom, which is Britain's gift to the world. Free markets and the aggressive pursuit of economic success within them are the central answers to Yali's question.

The question of why and how these ideas caught on or did not occupies the bulk of Conquests and Cultures. Some of the...