Goods and Services Tax Effects on Goods and Services Included in the Consumer Price Index Basket

This paper quantifies the magnitude and duration of the GST effect on the quarterly growth rate of the eleven groups of the consumer price index (CPI) in Australia using the Box and Tiao intervention analysis. It was found that prices did not increase significantly before or after the introduction of GST beyond what could have been expected on the basis of the discernible systematic pattern of fluctuation in the data. Furthermore, the varying one-off effect of GST on prices was significant in seven out of eleven CPI groups, the effect was found insignificant for the other four CPI groups.