Ben S. Bernanke focuses on some lessons economists have drawn from the Volcker regime regarding the importance of credibility in central banking and how that credibility can be obtained. Alan S. Blinder emphasizes that Paul Volcker retaught the world something it seemed to have forgotten at the time: that tight monetary policy can bring inflation down at substantial, but not devastating, cost. Bennet T. McCallum contrasts mainstream models used now for policy analysis with ones used in 1979.