The process of economic growth is inextricably linked to the growth of capitalist surplus, that is as long as the capitalist surplus increases, the national income also increases raising the growth of the economy.
The increase in the size of the capitalist or industrial sector in comparison to the subsistence sector may turn the terms of trade against the capitalist sector and therefore force the capitalists to pay the workers/laborers a higher percentage of their product in order to keep their real income constant.