This dissertation examines John S. Furnivall's theory of social and economic change in plural societies, societies in which peoples of different cultures live without sharing a common culture. The theory of plural economy can be derived from Furnivall's interpretation of social and economic change in colonial Burma (now Myanmar) and Indonesia (formerly Netherlands India). Furnivall's ideas were based on his experience (his career in Burma as an officer in the Indian Civil Service) and his life-long study of colonial policy and practice. Yet Furnivall's approach to the study of economic change is strikingly similar to that of Karl Polanyi and the American institutional economists. This dissertation will articulate and analyze Furnivall's theory of plural economy, and then compare Furnivall's ideas with the ideas of Polanyi and such major contributors to American institutional economics as Thorstein Veblen, John R. Commons, and Clarence Ayres. Connecting Furnivall's theory of plural economy with the more general theory of economic change provided by institutional economics is the major contribution of this dissertation. Placing the theory of plural economy within this larger context provides a new perspective on Furnivall's interpretation of social and economic change under colonial rule. But there is a mutual contribution between Furnivall and institutional economics. The institutionalist perspective contributes to a deeper understanding of the theory of plural economy by making the ideas upon which it is based more clear for the contemporary reader. Furnivall's analysis, in turn, provides one of the best examples of how economies can be studied as cultural phenomena. His work can thus be seen as one of the most important contributions to institutional economics in the field of economic development. The plural society was a common result of the colonial experience. Furnivall's theory of plural economy developed through his efforts to explain social and economic change within the colonial context Furnivall's ideas take on greater significance, however, as the plural character of many societies in the contemporary world becomes more pronounced. Examining past experiences of the peculiar dynamics of the plural society thus becomes increasingly important for understanding pluralism in the world today.