This study’s findings were contrary to our initial theory that the initial severity and the average severity of rivalries were both linked to increased rivalry duration. Second, my findings were contrary to previous studies indicating that polity changes may increase rivalry duration. Third, this study found, in accordance with previous studies that as rivalries increase in duration, the probability that they will terminate increases. The results of this study suggest that the measure of severity used in this study may not adequately reflect the total cost of all losses incurred from the escalation of a rivalry and that future research is needed to clarify the relationship between polity changes and rivalry termination. Future research on the effect of gains and losses should include multiple measures of losses and include not only number of casualties, but the loss of political and economic capital, losses in territory, and material goods.