This dissertation consists of four chapters, and the first chapter gives a brief summary of the dissertation. Chapters 2 and 3 analyze the Nash bargaining problem with endogenously determined threats in the n-person case. Chapter 4 discusses seemingly inconsistent behavior in voting for incumbents and for term limitation. In Chapter 2, we provide two bargaining models with variable threats in the n-person case: commitments to threat strategies are available and required in the first model, but they are not available in the second one. We formulate these two models as extensive games, and give two sets of axioms for the solution concepts in these models. The two sets of axioms uniquely determine the Nash bargaining solution relative to an equilibrium threat and relative to a Nash equilibrium of the underlying noncooperative game, respectively, in the first and second models. Furthermore, we show that when the number of players is large, in a game with side payments, the difference between the two models becomes insignificant. In Chapter 3, we discuss the voluntary decisions of commitments to threat strategies in Nash bargaining. Players are allowed to choose whether or not to commit to threat strategies. We consider three possible extensions where the voluntary decisions of commitments are included. In the two-person case, both players choose to commit to threat strategies voluntarily in all three extensions. However, an example is given to show that this is not the case for more than two players; the result depends upon an extension. In Chapter 4, we try to explain seemingly inconsistent behavior in voting for incumbents and for term limitation. Voters in several states voted recently for the introduction of a term limit, while at the same time, re-electing a large percentage of their incumbents. We formulate the candidate election within a district as a two-person game and integrate the results of the election games over all districts in a state. By doing so, we explain the voting behavior of voters in the candidate election and in the term limitation election, based on the assumption that voters are self-interested in both elections. / Ph. D.