As the global depression deepened, the seeming failure of competitive markets to restore full employment perplexed economists until John Maynard Keynes offered an explanation that was to influence policy practitioners for generations to come. He argued that, contrary to the tenets of Smith and his followers, market systems did not always converge to full employment.
They often appeared to settle at an equilibrium in which significant segments of the workforce were unable to find jobs. In the place of Smith's laissez-faire approach arose the view that government action was required to restore full employment and to rectify what were seen as other deficiencies of market-driven outcomes.