Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
Existing theories explain the rise and fall of states either by random factors specific to each state or by a life cycle to which any state eventually succumbs. However, neither approach is able to explain systematic patterns such as the tendency toward smaller political units during the millennium from 400 to 1400 A.D. and the movement in the opposite direction over the last six centuries. Here it is argued that such changes are due to innovations in the technology of information processing and military control that alter the cost of generating rewards and imposing punishment. Copyright 1992 by Kluwer Academic Publishers