Named after American economist Robert Solow (1924- ), Solow economic growth highlights the relationship of technological change to growth.
As the rate of return falls, firms turn to more capital intensive methods of production; therefore the rate of investment increases.
However, it is possible to show a situation in which the rate of return would be such that firms would reduce their level of capital intensity, causing investment and the rate of return to decline; this is called capital reswitching.
Also see: roundabout method of production
R M Solow, Growth Theory: an Exposition (Oxford, 1970)