1500 year old markets

From the New York Times comes a report that the ancient Maya civilization may have had a market economy,

Scientists using improved methods of analyzing the chemistry of ancient soils have detected where a large marketplace stood 1,500 years ago in a Maya city on the Yucatán Peninsula of Mexico.

The findings, archaeologists say, are some of the first strong evidence that the ancient Maya civilization, at least in places and at certain times, had a market economy similar in some respects to societies today.

Arnold Kling isn't buying into this. He writes,"I just don't believe that over a thousand years ago human beings had the trustworthiness, discipline, numeracy, and institutional base to engage in what we would today recognize as free trade." I'm not sure why. In his book, The Origins of Human Society, Peter Bogucki writes

One of the major advances in Maya research has been the identification of early trading networks, since the procurement of status goods such as jadeite, marine shell, quetzal feathers, and obsidian was linked with the emergence of elites. The site of Cerros, on the Caribbean coast of Belize, is particularly significant (Robertson and Friedel 1986). It lies on Chetumal Bay near the mouths of the New River and Rio Hondo, which lead into the interior of Belize. Not only was it well-suited to engage in coastal trade between the salt-producing areas of Yucatan to the north and the source area of obsidian and jade in Guatemala and El Salvador to the south, but from this location goods could also move into the interior of Belize and northern Guatemala. (p.348)