"Measuring Business Conditions and A Smoothing Problem : A Case of Japanese GDP" (in Japanese)

The Japanese Government reports the annualized estimates of the growth rates of GDP and its main components once in 3 months, and then revises them once in a while. There have been some critical comments on the accuracy of those numbers mainly from economists who want to evaluate the current business conditions in Japan. We suggest possible reasons why those estimates fluctuate unexpectedly in recent years and then we propose a new statistical method of estimating the annualized growth rates of GDP and its components.