Describe the Lewis model of economic development.

W. A. Lewis is the inventor of Lewis model and it is based on the theory of dual sector in which he divided the economy of an underdeveloped country into 2 sectors: the capitalist sector and the subsistence sector. The Lewis model explains the growth of a developing economy in terms of a labour transition between these two sectors. Lewis defined this sector as "that part of the economy which uses reproducible capital and pays capitalists thereof". The use of capital is controlled by the capitalists, who hire the services of labour. It includes manufacturing, plantations, mining etc. The capitalist sector may be private or public. This sector was defined by him as "that part of the economy which is not using reproducible capital". The "Dual Sector Model" is a theory of development in which surplus labor from traditional agricultural sector is transferred to the modern industrial sector whose growth over time absorbs the surplus labor, promotes industrialization and stimulates sustained development.