Credibility of Optimal Monetary Delegation: Comment
评论Jensen（1997）关于货币委托不能解决时间不一致问题的观点，指出其结论源于对政府政策行动范围的限制；放宽限制后，委托政策反而能在低贴现因子经济中实现零通胀。
In his recent paper in the American Economic Review, Jensen (1997) argues that delegation of monetary policy to an independent central bank, which acts as an agent for the government, does not mitigate the problem of time-inconsistency, but merely relocates it. ∗We acknowledge with thanks support for this work provided through ESRC research grant L138251003 “Imperfect Financial Markets, Business Cycles, and Growth”, which forms part of the programme on Understanding the Evolving Macroeconomy (UEM). We are grateful to participants at the Money, Macro and Finance (MMF), and UEM Conference 2002 for their helpful comments. We thank also the editors and referees of this journal for their advice and suggestions. An Appendix containing details of algebraic derivations in Section 4 of this paper can be found on the AER web site and on the authors’ site at www.econ.bbk.ac.uk/faculty/driffill 1 He examines a government that delegates monetary policy to an in-dependent central bank, and that faces costs if it interferes in the policy decisions of the bank by appointing a new central banker to obtain a preferred result. He shows that delegation makes it more dif-ficult to sustain the credibility of optimal monetary policy. We show here that this result emerges because Jensen examines a restricted range of policy actions for the government. When this restriction is lifted, the result is reversed. By means of suitable announcements of contracts for the central bank, combined with appropriate actually implemented contracts, delegated policy enables zero inflation to pre-vail in economies in which it could not do so without delegated policy. These economies are ones that have relatively low discount factors.