States are not simply created and manipulated by dominant classes; they are agents in their own right, and they compete with the elites in appropriating resources from the economy.

Additional factors facilitating the spread of disease are the movements of armies and the expansion of international trade. The latter factor should be qualified by noting that international trade expands in the precrisis period (stagflation phase) and then gradually declines after the society has descended into anarchy. Thus, the rise of

Thus, we can use trends in higher education as an index of intraelite competition (Goldstone 1991:123).

the increasing extravagance of noble consumption.

There must also be some vulnerability of the state in the form of internal divisions and economic or political reverses. Otherwise, popular discontent is unvoiced, and popular opposition is simply suppressed.

Our explicit focus is on agrarian societies, that is, those in which more than 50 percent of the population (and typically above 80–90 percent) is involved in agriculture.

As a result, food prices increase, real wages decline, and per capita consumption, especially among the poorer strata, drops. Economic distress leads to lower reproduction and higher mortality rates, resulting in a slower population growth.

But, second, as general population grows closer to the carrying capacity, surplus production gradually declines. The combination of these two trends results in an accelerating fall of average elite incomes.

the social structure, the most important part of which was the surplus-extraction relationship between the direct producers and the ruling class (Brenner 1985a:10–11).