After assessing Sonora's industrialization, this paper explores whether, during the period from 1993 to 2003, its municipalities have tended towards a greater or lesser differentiation in their added manufacturing value, and whether this pattern has been influenced by the criteria for geographical allocation of state investment in infrastructure. It uses this information to review the policies that in theory, should serve as a counterweight to regional disparities. It concludes that, although the rate of municipal convergence in Sonora is relatively high, it has tended to decline. It also confirms the state's limited capacity to use its resources, to influence the regional pattern of manufacturing development. [ABSTRACT FROM AUTHOR]