The word ‘market’ may mean three things: first, the place at which the commercial exchange of goods takes place; secondly, the forces of supply and demand that govern the commercial distribution of goods. ‘Market’ in the second sense gives rise to another meaning of the word: the geographical area in which the commercial exchange of certain goods operates. This book is mainly concerned with the market of grain in the second and third senses. The reader may be expecting to find an analysis of the price formation of various grains, a survey of the short-term trends and long-term developments of prices and real wages, a study of the processes of the cereal market, and a quantitative outline of imports and exports of grain between agricultural regions and structural markets. However, the reader should be warned that the present study of the grain market in the Roman world contains little of the above. This is not by choice, but by necessity: the ancient sources simply contain insufficient data to undertake an analysis of those aspects of pre-industrial societies that most economic historians of later times regard as essential.

The reason is that most ancient sources are literary texts, which include not only works of philosophy, history, novels and letters, but also legal writings and texts inscribed on stone. Even Egypt, while offering by far the most quantitative evidence on the ancient world, does not yield sufficient documentary sources to undertake a serious attempt at statistical analysis (except maybe on demography).