In this research the investigators propose a new theory of coalition formation in order to understand the process by which governments are assembled in multiparty parliamentary democracies. The literature on coalition theory is a rich one, extending back more than thirty years. To date, however, this literature has not come to grips with the fact that government coalitions are different from coalitions in general - - that the forming of a government is a vastly different event from that of passing a legislative bill or dividing up a pie. These latter events may be thought of as "terminal" - - once a bill is passed or a pie divided, business is essentially done. In forming a government, however, the processes of politics have only just begun. Thus, in thinking about government formation, it is essential that one incorporate the rational beliefs and expectations of the actors concerning what will happen once the government is installed. This observation allows the Principal Investigator to formulate a theory of strategic bargaining by the various parties elected to a popular assembly. Their objective is to form a government, which action requires a majority vote of support in the assembly. The various actors couch their support or opposition to a proposal for a new government in terms of their beliefs of what results will flow from installing this group of parties as opposed to that group of parties. But where are these beliefs about the future to come from? This is the crucial aspect of the research by the investigators. They define and elaborate the notion of credible promises and use this concept to develop a theory of how the various forces inside a popular assembly combine to form a government. Besides its contribution to basic knowledge, this research is of pactical significance as more and more parts of the world turn to parliamentary institutions in which many (rather than just two) parties contest for power and governmental leadership.