Product Replacement Bias in Inflation and Its Consequences for Monetary Policy
研究了新产品进入和旧产品退出导致统计部门延迟观测，使测量通胀出现偏差，进而影响货币政策效果，发现按测量指标制定政策虽不能充分稳定总体通胀，但能改善福利。
The paper examines a New Keynesian model with product entry and exit and with two types of households. Households consume different product baskets, and therefore, face different inflation rates. The statistical bureau used in the model measures aggregate inflation, but observes product entry with a probabilistic delay. Consequently, measured inflation suffers from product replacement bias with respect to aggregate inflation. Measured inflation is less volatile but more persistent than aggregate inflation, and the correlation between aggregate inflation and aggregate output is lower than the correlation between measured inflation and measured output. When monetary policy responds to measured variables, it stabilizes aggregate inflation insufficiently. Nevertheless, under discretionary monetary policy, responding to measured variables improves welfare.