MICHAEL SHILMAN
THE STATISTICAL EVIDENCES FOR THE GLOBAL RHYTM OF POLITICAL CENTRALIZATION
The high correlation between long-time changes of the total urban population and the exponents of empires' size which is demonstrated by C. Chase-Dunn and founded on the data of T. Chandler and R. Taagepera, confirms the cyclical character of political centralization. This effect is introduced by the inphase curves. There is a good evidence that it corresponds with the dynamics of nomads' invasions toward urbanized areas (E. Chernykh's C-waves). The Eurasian scale 400 BC to 1400 AD demonstrated the synchronism of these cycles. We deal with two interdependent questions. First, we try to find out the additional parameters of historical systems bearing on the model of cycles of political centralization. Second, taking the new data into consideration we expand the series of these cycles to past in order to mark their basic points. Statistical examination of the history of more than 240 sovereign states shows the cycles of grows and decline of their total number for the period of 1600 BC 800 AD. By the same method we investigate the complex of more than 40 demographic cycles from S. Nefedov's data. As a result we detect the periodical changes of the total number of their cycles (1400 BC 1400 AD). The comparing of the mentioned curves and the analysis of the variations of the parameters allow us to make a conclusion that the overseen global cycles can be fixed for the period of 1400 BC 1400 AD, and the duration of each cycle is about 600-700 years.