(December 2006 - February 2007)The Balochistan Economic Report is an extensive study of the economic performance and growth potential of Balochistan. It is part of Asian Development Bank's technical assistance to Balochistan to help define the immediate and long term development agenda for the province. The study has been carried out in collaboration with the World Bank. The Background Paper on Social Structures and Migration examines the main internal political obstacles to the social and economic development of the province. It proposes a political-economy framework for interpreting Balochistan's economic potential, arguing that all the key sectors and activities that might contribute to growth in the province are those that are related to the creation and realization of economic rents. It examines tribalism and ethnicity as possible sources of political fragmentation and social stagnation and elaborates upon Balochistan's actual experience with tribalism and ethnicity using a range of material including micro-level observations from fieldwork, key informant interviews and historical narratives. The paper also discusses migration and its interplay with existing social structures and economic development, and reviews the political processes and outcomes - conflict, consensus-building and accommodation respectively. It concludes with observations on the dynamics of institutional change and the potential for social and economic development of the province.