This chapter presents demographic conditions as a determinant for economic performance in the ancient Greco-Roman era. It focuses on the relationship between demographic structures and macro-economic features. The chapter first outlines the fundamental demographic characteristics of the Greco-Roman world. Next, it presents a theoretical model of the interdependence of economic and demographic development. Finally, the chapter explores the model's principal variables in the context of ancient Mediterranean economies. Mean life expectancy at birth is conventionally put in the range of 20-30 years. From the middle of the second millennium BC to the early first millennium AD, all parts of the Mediterranean and its hinterlands experienced significant demographic growth. The baseline upward trend in ancient population number is modulated by two distinct layers of variation in the short and medium terms. Several features including mortality, morbidity, nutrition, housing and clothing, point to significant improvements in well-being in the Greek Aegean between the tenth and the fourth centuries BC.

A sensitivity to grain crises and the rapid and dynamic reactions may be responsible for the apparently somewhat chaotic and uneven growth. Such a characteristic of early medieval demographic evolution is probably partly responsible for the fact that these fluctuations cannot be determined or delimited chronologically. The prevalence of pigs in comparison to sheep and especially to cattle, on both desmesne land and farms held in tenure, points to mixed farming in which the stock economy was subordinate to an agricultural economy centred on grain production. From about the middle of the eighth century onwards, the structure and exploitation of land ownership in the Frankish empire between Loire and Rhine, between Rhine, Elbe and Alps, and in northern and central Italy underwent profound changes. As a result of the dominant role of manorial organisation in agrarian and industrial production, the exchange of goods and trade were also to a large extent dependent on the large estate and its production.