The purpose of this paper is to examine some earlier efforts to measure the inequality of distribution within several different substantive contexts and to see how appropriate these different measures might be if they were applied to the distribution of "power potential" in the international system or any of its subsystems. We discuss several measures which we find would not be appropriate. We then present a measure which we find better suited for the purpose and go on to compare it to earlier measures of inequality. Several of these turn out to be very similar to the one we present, even though they were originally devised for quite different purposes, such as measuring the degree of economic differentiation in a society. We conclude with a demonstration of the essential similarities among most of the measures discussed.