Knowing the weight of a commodity provides an objective way to value goods in the marketplace. But did a self-regulating market even exist in the Bronze Age? And what can weight systems tell us about this? A team of researchers from the University of Göttingen researched this by investigating the dissemination of weight systems throughout Western Eurasia. Their new simulation indicates that the interaction of merchants, even without substantial intervention from governments or institutions, is likely to explain the spread of Bronze Age technology to weigh goods. The results were published in Proceedings of the National Academy of Sciences (PNAS).