Efforts to make aid more effective in the last two decades have given prominence to "country ownership." With true country ownership, aid is supposed to follow the priorities of recipient countries, rather than those of the funders. Yet funders have their priorities too. So recipients and funders have sought to resolve this potential conflict through policy dialogue and alignment of priorities. My new paper, "What is 'Country Ownership'?" explores this basic problem using a formal model to unravel three interrelated factors affecting country ownership.