Policy designers seeking to harness profit-driven efficiency for public purposes are increasingly creating organizations with fractionalized property rights that distribute "ownership" among public and private actors. The resulting hybrids are quite diverse, including mixed enterprises, public-private partnerships, social entrepreneurship organizations, government-sponsored enterprises, and various other hybrid forms. Marrying public purposes to private sector efficiency and strategic flexibility provides a tempting rationale for mixing public and private owners in hybrid organizations. Because public-private hybrids involve fractionalized property rights, however, they exhibit tension among owners over both strategy and, more importantly, goals. To understand public-private hybrids, we assess them in terms of six dimensions of property rights: fragmentation of ownership, clarity of allocation, cost of alienation, security from trespass, credibility of persistence, and autonomy (of both owners and managers). The unclear allocation of fractionalized ownership rights facilitates the appropriation of financial residuals and asset ownership opportunistically. Other weaknesses in the property rights configurations of public-private hybrids create managerial dissonance or opportunistic behavior that typically leads to a narrowing of goals, but sometimes also to organizational failure.