Keynesian models with sticky prices are favored over real business cycle models because they better match data. Studies by Gali, Basu, Fernald, Kimball, and Mankiw show that labor effort and productivity are negatively correlated, suggesting sticky prices. However, the correlation depends on the type of monetary policy assumed. Different policies can lead to different outcomes, challenging the conclusions drawn by previous studies. The choice of monetary policy is crucial in determining the dynamic behavior of the economy.