weaken economic interdependencies within regions, at least in regions without a great power. Additionally, as multipolar systems can tend to regional hegemonies or bounded orders, agreements are formed within these bounded orders rather than globally. Though, Mearsheimer predicts the persistence of a thin international order within multipolarity, which constitutes some multilateral agreements. Measuring the power concentration The Correlates of War uses a systemic concentration of power formula to calculate the polarity of a given great power system. The formula was developed by J. David Singer et al. in 1972. t = the time at which the concentration of resources (i.e. power) is being calculated i = the state of which the proportion of control over the system's power is being measured Nt = the number of states in the great power system at time t S = the proportion of power possessed. Hence, Sit = the proportion of power possessed by state i at time t. The expression represents the sum of the squares of the proportion of power possessed by all states in the great power system. The closer the resulting concentration is to zero, the more evenly divided power is. The closer to 1, the more concentrated power is. There is a general but not strict correlation between concentration and polarity. It is rare to find a result over 0.5, but a result between 0.4 and 0.5 usually indicates a unipolar system, while a result between 0.2 and 0.4 usually indicated a bipolar or multipolar system. Concentration can be plotted over time, so that the fluctuations and trends in concentration can be observed. See also Balance of power (international relations) Global policeman International monetary systems Non-Aligned Movement Pax Americana Pax Britannica Power (international relations) Posthegemony Regional hegemony Thucydides Trap Bibliography Thompson, William R. On Global War: Historical–Structural Approaches to World Politics. Columbia, SC: University of South Carolina Press, 1988, pp. 209–210. Notes References External links Global Power Barometer International relations theory