We develop a game-theoretic model of private-public contribution to a long-term project with sequential actions and moral hazard. A private agent is one who is in charge of both the financial contribution and the management effort, these two actions entailing private costs and uncertain ex-post private and social benefits. A public agent is one who decides the amount of public funding to this quasi-public good, knowing that the size and the probability of attaining a surplus ex post depend on the private agent's effort. We consider four public-funding scenarios: benefit-sharing versus cost-sharing crossed with ex-ante versus ex-interim government intervention. We test our theoretical predictions by means of an experiment that confirms the m...