This report develops a framework to examine the role of policy at three levels: at the level of agricultural policy basics (Section 2); at the level of directly shaping investments (Section 3); and at the level of market governance (Section 4). The key policy levers are summarized in Table 1, and elaborated on at the end of each section. The work was supported by four country case studies, conducted in Guatemala, Nigeria, Tanzania, and the Philippines, and led by national researchers.