Countries everywhere are divided within into two distinct spatial realms: one urban, one rural. Classic models of development predict faster growth in the urban sector, causing rapid migration from rural areas to cities, lifting average incomes in both places. The situation in South Africa throws up an unconventional challenge. The country has symptoms of a spatial realm that is not not rural, not fully urban, lying somewhat in limbo. This is the realm of the country's townships and informal settlements (T&IS). In many ways, the townships and especially the informal settlements are similar to developing world slums, although never was a slum formed with as much central planning and purpose as were some of the larger South African townships. And yet, there is something distinct about the T&IS. For one thing, unlike most urban slums, most T&IS are geographically distant from urban economic centers. Exacerbated by the near absence of an affordable public transport system, this makes job seeking and other forms of economic integration prohibitively expensive. Motivated by their uniqueness and their special place in South African economic and social life, this study seeks to develop a systematic understanding of the structure of the township economy. What emerges is a rich information base on the migration patterns to T&IS, changes in their demographic profiles, their labor market characteristics, and their access to public and financial services. The study then look closely at Diepsloot, a large township in the Johannesburg Metropolitan Area, to bring out more vividly the economic realities and choices of township residents. Given the current dichotomous urban structure, modernizing the township economy and enabling its convergence with the much richer urban centers has the potential to unleash significant productivity gains. Breaking out of the current low-level equilibrium however will require a comprehensive and holistic policy agenda, with significant complementarities among the major policy reforms. While the study tells a rich and coherent story about development patterns in South African townships and points to some broad policy directions, its research and analysis will generally need to be deepened before being translated into direct policy action.