State History Index, aggregate index of state history in the year 2000, and discounted values of the overall country indicators with the discounting rates of 10%.

The construction of the index follows the principles developed by Bockstette et al. (2002). First, the duration of state existence (from state emergence to 2000 CE) was established for each territory defined by modern-day country borders. From the state emergence onwards, the authors assigned scores to reflect three dimensions of state presence, based on the following questions:
1) Is there a government above the tribal level? (Score component z1 receives 1 point if yes, 0.75 if the government can at best be described as a paramount chiefdom and 0 points if no government is present);
2) Is this government foreign or locally based? (z2 is 1 if the rule is locally based, 0.5 if externally based, and 0.75 for local government with substantial foreign oversight);
3) How much of the modern country's territory was ruled by this government? (z3 reflects the proportions of the territory under some rule: 1 (over 50 percent), 0.75 (25-50 percent), 0.5 (10-25 percent), 0.3 (under 10 percent).

The discount rates refer to a technique used to account for the different time periods to which a variable may refer to in order to create an aggregate index. More information about the discount rate used for this dataset can be found at https://sites.google.com/site/econolaols/extended-state-history-index