In this dissertation, I investigate a key distinction in the electoral origins of governing coalitions: whether bargaining among parties to form the government is primarily pre-electoral or post-electoral. Post-electoral bargaining refers to competing parties negotiating to form a governing coalition after an election. Pre-electoral bargaining involves parties committing before an election to govern together as a unit. In the first part of the dissertation, I argue that parties form pre-electoral pacts with an eye to gain portfolios, conditional on electoral costs. These costs vary in predictable ways tied to variations in the structure of the world's electoral systems. In the second part, I present two main findings on the consequences of the electoral origins of governing coalitions. First, pre-electoral coalitions are more proportional in their internal allocation of offices. I argue that this distribution of spoils is designed to encourage contributions to winning elections rather than purely legislative contributions to majorities. Second, I argue that the more pre-electoral a coalition, the more it is likely to take a majoritarian 'bonus' in the distribution of offices in the legislature. Cross-national empirical analyses are conducted on samples of coalitions from developing and advanced democracies since the 1990s