Lonely planet guide for Thus, subsistence wage can increase over the years as the social and cultural definition of what is required for subsistence changes in a society. In the 20th century, Lewis renewed the focus on issues of subsistence wage with his two-sector growth model. This pioneering work laid the foundation for the vast literature on development economics. The theory provides a framework for a developing economy to increase economic growth using the existing resources within the nation. The Lewis model assumes that the economy is divided into two sectors, a rural agricultural sector and an urban industrial sector. The rural sector is characterized by high level of unemployment and workers earning a subsistence wage rate. The workers in this sector have very low marginal productivity. Lonely planet guide 2016.