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Too Many Cooks? Committees in Monetary Policy Helge Berger and Volker Nitsch. Discussion by Christopher Crowe, IMF Research Department* for Conference on Central Bank Communication, Decision-Making and Governance , Waterloo University April 28-29 2009.
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Too Many Cooks? Committees in Monetary PolicyHelge Berger and Volker Nitsch Discussion by Christopher Crowe, IMF Research Department* for Conference on Central Bank Communication, Decision-Making and Governance, Waterloo University April 28-29 2009 * Does not necessarily reflect the views of the IMF, its management or Executive Board.
Summary of the paper • Paper’s key contribution is a new dataset covering >30 countries for up to 40 years • De facto as well as de jure committee size for CB MPCs • Composition of MPC (industrial, regional, institutional background) • Principal Use of the Data: is there an optimal committee size for inflation control?
Main Results • U-shaped relationship for inflation: minimized at 8-10 committee members. • Similar U-shaped relationship for inflation volatility. • Inverse-U for output growth. • Higher MPC member turnover associated with lower inflation (opposite of result with governor turnover). • Composition of MPC (e.g. government representation) has little impact.
My comments • Very interesting paper on an important topic. • The dataset could be used to shed light on several interesting questions relating to committees, decision-making and central bank governance… • …but I’m not wholly convinced that the paper’s main question is the right one to ask with this data. • Plus a few other comments.
Are the main results convincing? • Why should committee size affect the level of inflation? • Committee too large: cannot communicate easily; subject to factionalism or defense of own interests. • Committee too small: cannot benefit from lower volatility of mean decision. • But why higher inflation rather than more volatile inflation or inflation that’s harder to predict? • Any plausible model of the inflation bias with committee size as argument? Or of output growth? • Omitted variable bias likely large compared to any genuine effect. • Easy to think of omitted variables: • “Institutions” (effectiveness of government sector) • Heterogeneity (has macro implications, might require large committee) • “Culture” (shapes views on decision-making and individual responsibility, also macro policy and outcomes). • Regressions have only a minimum set of reasonable controls.
What could be driving the results? • Inflation bias can be caused by inappropriate output gap target • E.g. because government is going for short run growth • CBI as remedy: devolve to conservative CB’er or one with appropriate objectives • If a government wanted to weaken CBI: • Have a small committee (less political cover for tough decisions; easier to replace with more compliant candidates) • Have a large committee (ineffective talking shop; agenda-setting by compliant governor/chairman). • i.e. committee of reasonable size more independent. • But committee size not ultimate causal factor.
What other questions are there? • Inflation and output volatility • (paper already looks at variance of inflation) • Inflation and output predictability (look at variance of forecast errors) • Combine with voting behavior (more limited sample): • Do larger committees vote differently (e.g. agenda-setting by chair?) • Do different types of MPC member vote differently? (e.g. Besley, Meads and Surico, 2007; Meade and Sheets, 2005). • MPC member turnover (some interesting results in the paper, I would give these greater prominence).
Some other comments • The baseline results could be made more convincing: • Cluster SE’s by country to capture country-specific patterns of serial correlation • Additional controls: • measures of governance • Political turnover measures • De jure CBI • Output gap rather than growth minus avg. growth • Use inflation tax transform π/(1+ π) to reduce impact of outliers • It would also be useful to have summary statistics for the main variables.