The economics of early social stratification

We develop an endogenous fertility model of social stratification with two hereditary classes: warriors and peasants. Our model shows that the extra cost warriors must incur to raise their children and to equip them for war is the key determinant of (1) the relative sizes of both classes, and (2) the warriors' economic privileges in terms of income and consumption. The higher the cost of warrior children, the greater the economic privileges of warriors will be, and the smaller the ratio of warriors to peasants will be. Historical evidence confirms this prediction.