The authors bring together and extend three strands of existing research: the propensity of democracies to ally with each other, the effects of alliances being institutionalized, and the causal impact of democracy in promoting investment. This literature is applied to corporate alliances, predicting the probability that announced alliance contracts will be completed by the participants. The authors find that democratic political regimes generate rules that create corporate shareholder democracy and that the latter promotes the institutionalization of corporate alliances. Corporate democracy and alliance institutionalization will both, controlling for transaction costs, increase the probability that corporate alliances will be completed. The findings suggest a positive association among democratic corporate governance, the willingness of corporate alliance partners to accept institutionalized ties, and the creation of an environment conducive to commercial investment commitments through alliances. Overall, corporations appear to respond to some of the same alliance incentives as sovereign states.