Comparison of X-12-ARIMA Trading Day and Holiday Regressors with Country Specific Regressors
Christopher G. Roberts, Scott H. Holan, Brian Monsell
Several methods exist which can adjust for trading day and holiday effects in monthly economic time series. This article reviews and compares two such methodologies for conducting proper adjustments. The two methodologies are based upon the U.S. Census Bureaus X-12-ARIMA method and one developed by the Statistical Offices of the European Communities, commonly referred to as Eurostat. Three different methods are used to compare the U.S. Census Bureau procedure and the Eurostat-inspired procedure. These methods are spectral analysis, sample-size corrected AIC comparisons, and examination of out-of-sample forecast errors. Finally, these comparisons are conducted using nearly 100 U.S. Census Bureau time series of manufacturing data, retail sales, and housing starts along with roughly 70 Organisation for Economic Co-operation and Development (OECD) European time series of manufacturing, retail sales, and industry data. This empirical study is the first of its kind and therefore provides an important contribution to the seasonal adjustment community.
Eurostat, holiday effect, model selection, regARIMA model, trading day effect