最优汇率制度选择理论与政策判研——基于目标区经典模型的修正

从传统金本位制至欧洲货币联盟汇率机制(ERM2),目标区制已成为当代有影响力的汇率制度.Krugman经典模型构建严密,充分体现了目标区制度稳定性与灵活性的完美结合,但由于其假设前提与现实脱离,因而后继者试图从多种角度拓展和修正之.研究说明,引入目标区不完全可信和边界内干预两个假设前提后,能构筑新的目标区综合模型,并将固定汇率制、自由浮动汇率制和有管理的浮动汇率制作为特殊形式纳入目标区统一框架,通过预期价值函数比较,最终证明目标区制是最优选择.该结论为人民币汇率制度后续改革提供了理论支撑和有益启迪.

A Study on the Theory and Policy of the Optimal Exchange Rate Regime ——A Revision Based on the Classical Target-zone Model

From the traditional gold standard up to the current EU's ERM2 arrangement,the target zone regime has already become an influential exchange rate regime.This paper presents a benchmark model that is based on the Krugman standard theory,and rationalizes the choice of target zone instead of other regimes owing to its fixed rate,and free and managed float.The target zone may be a cause of stabilizing or destabilizing exchange rate expectations,which crucially depends on the within-band central bank policy as well as the credibility of commitment to defend the target zone.