Analysis of the Price Data

The three sections that follow try to answer different sets of questions about the price history of the three commodities. The first section explores the fluctuations of price within a year. Several interesting patterns emerge, which can be accounted for by appeal to the structure of the seasonal market for each good; as we shall see, harvest dates and the sailing season prove crucial for the seasonal price curve for some commodities.

In the second section I study the long-run trend of prices over the whole period of independence. For these purposes I use mean annual prices to dampen the impact of large but transient fluctuations in monthly prices, and to permit the inclusion of years preserving only a few (or even only one or two) individual prices. The results, which depend in part on the application of techniques of linear regression, partly support and partly refute traditional interpretations of price histories.

The discoveries of the second section lead directly to a brief examination of the interrelations among the price histories of all three goods. On the basis of the available data, I propose a set of hypotheses that may account for price movements and relations among the prices of the three commodities. In particular, there seems good reason to postulate a break in earlier interconnections around 220–200 B.C. The transformation fits well with certain other indications of a changed economic scene on Delos by ca. 220 B.C. , a matter that will come in for further treatment in chapter 7.