[1][2][3] It states that in the long run productivity generally grows proportionally to the square root of output.
[5] Verdoorn's law describes a simple long-run relation between productivity and output growth, whose coefficients were empirically estimated in 1949 by the Dutch economist.
[6] Verdoorn's law differs from "the usual hypothesis […] that the growth of productivity is mainly to be explained by the progress of knowledge in science and technology",[7] as it typically is in neoclassical models of growth (notably the Solow model).
Verdoorn's law is usually associated with cumulative causation models of growth, in which demand rather than supply determine the pace of accumulation.
Nicholas Kaldor and Anthony Thirlwall developed models of export-led growth based on Verdoorn's law.