Basic Issues on the Seasonal Adjustment of the Canadian Consumer Price Index

Abstract

This study is mainly concerned with basic issues that arise in connection with the seasonal: adjustment of the Canadian Consumer Price Index when used as a current indicator of inflation. It analyzes the seasonal characteristics of the series and evaluates whether a direct or an indirect adjustment is preferred from the viewpoint of the degree of smoothness of the monthly rate of change. The use of ARIMA extrapolations versus no ARIMA extrapolations and the application of concurrent versus year-ahead seasonal factors are also discussed. The selection of the optimal procedure is made according to the degree of smoothness and size of the revisions of the seasonally adjusted monthly rate of change.

KEY WORDS:

• X-11-ARIMA—direct versus indirect adjustment
• Concurrent seasonal factors
• Smoothness measures
• Revision measures