How Wealth Happened in Neolithic Central Europe // JOURNAL OF WORLD PREHISTORY, DOI: 10.1007/s10963-011-9047-5 (2011)
Peter Bogucki
This paper advances the proposition that three key technological and logistical systems matured during the fourth and third millennia BC in Late Neolithic/Copper Age Europe: transportation infrastructure, durable goods made of metals, and capital investment in oxen used for traction. As risk rather than uncertainty became the dominant condition under which decisions were made, the convergence of these factors permitted individuals and households to accumulate genuine wealth.
http://www.springerlink.com/content/48713262p5425330/