Different parts of the region specialized in one kind of metal production and traded with the others for the other metals they needed. They didn't have a single ruler but were each self ruling.

Thank you. I was familiar with Ricardo but didn't understand the word spaghetti about metals in the article.

In the old model of metal age, metals are developed by a society that is hierarchical or militaristic (as development of metal is a very complex process with specialized knowledge and tooling). This old model cannot be applied to an archaeological site in Thailand (Ban Chiang / Ban Non Wat / etc.) due to evidences demonstrating absence of control over metal production in the region.

The research paper suggested that the region developed its metal age by trading rather than by any ruling entity, by applying Ricardo's Law to the distribution of metal artifact in the region.

Ricardo's law is the advantage of specialization. If A can produce more value by producing X instead of Y, it is best to produce the former and buy the latter - that efficiency in production creates a possibly counter-intuitive extra for both trading parties.

«In this kind of economy, communities specialize in producing certain goods in order to participate in the regional exchange system [...] they see their efforts are better spent in producing other products to exchange for desired goods made in other villages or regions. [...] development of a regional economic system rooted in exchange networks among communities underpinned the peaceful heterarchical metal age socio-political system that endured in Thailand for over two millennia»