The analysis and conclusions of the preceding chapter on the treatment of the concept of the rate of profits and its implica­ tions for economic growth in mature capitalist economies can now be utilised in the discussion of the models of economic growth put forward by modern neoclassical theorists. The grouping of the following writters such as Meade, Tobin, Solow, Samuelson and Modigliani (many of whom prefer to wear the Keynesian label) as neoclassicists is in regard to their approach to the concept of capital and the rate of profits as the return to capital or more precisely as equal to the marginal product of that substance called capital.