Small enterprises typically make a large contribution to manufacturing employment in poor countries. However, the developmental contribution of most of them is limited to generating subsistence employment "of last resort". Hence, in the face of fast labor force growth and limited employment absorption in other sectors, developing country governments have mounted efforts to improve productivity and earnings in these firms. This has spawned a plethora of policies and programs, and an almost boundless literature documenting them. This paper is a review of one specific subset of that literature.