Why does low central bank independence generate high macroeconomic instability? A government may periodically appoint a subservient central bank chairman to exploit the inflation-output trade-off, which may generate instability. In a New Keynesian framework, time-varying monetary policy is connected with a “chairman effect.” To identify departures from full independence, I classify chairmen based on tenure (premature exits), and the type of successor (whether the replacement is a government ally). Bayesian estimation using cross-country data confirms the relationship between policy shifts and central bank independence, explaining approximately 25 (15) percent of inflation volatility in developing (advanced) economies. Theoretical analyses reveal a novel propagation mechanism of the policy shock.