Harrod's dynamics and the theory of growth: the story of a mistaken attribution

Post-Keynesian growth theory is normally seen as originating from Harrod's 1939 'Essay in Dynamic Theory'. Harrod, however, was trying to lay the foun dations of a new approach to economic dynamics, and often complained of mis interpretation. In this paper, the grounds of Harrod's argument are examine d and compared with the 'textbook' interpretation. The latter is shown to b e extremely reductive, as it ignores both Harrod's interest in the trade cy cle and his methodological criticism of the 'time-lag theories of the cycle ', and it also underrates the interesting implications of his non-linear ap proach and the epistemic implications of the instability principle.