- We analyze a large data set of commercial records produced by Assyrian merchants in the nineteenth century BCE. Using the information from these records, we estimate a structural gravity model of long-distance trade in the Bronze Age. We use our structural gravity model to locate lost ancient cities. In many cases, our estimates confirm the conjectures of historians who follow different methodologies. In some instances, our estimates confirm one conjecture against others. We also structurally estimate ancient city sizes and offer evidence in support of the hypothesis that large cities tend to emerge at the intersections of natural transport routes, as dictated by topography. Finally, we document persistent patterns in the distribution of city sizes across four millennia, find a distance elasticity of trade in the Bronze Age close to modern estimates, and show suggestive evidence that the distribution of ancient city sizes, inferred from trade data, is well approximated by Zipf’s law.
From within the article:
- Of the 25 cities in our sample, 15 are known and 10 are lost. Known cities are either cities for which a place name has been unambiguously associated with an archaeological site, or cities for which a strong consensus among historians exists, such that different historians agree on a likely set of locations that are very close to one another. Lost cities, on the other hand, are identified in the corpus of texts, but their location remains uncertain, with no definitive answer from archaeological evidence. From the analysis of textual evidence, archaeology, and the topography of the region, historians have developed competing hypotheses for the potential location of some of the lost cities. We propose using data on bilateral trades between known and lost cities and a structural gravity model to inform the search for those lost cities.