Note 1-18

18 Some of the specific information that the GDP carries and that distinguishes it from the consumer price index, can be summarized as 1） the fact that it represents "home-made inflation," or in other words, inflation that excludes the impact of import prices, and 2） the fact that it represents prices not only of consumer goods, but also of investment goods, etc. However, it can be pointed out that 1） if temporary increases in import prices (e.g. oil prices) and other types of impacts are to be examined separately, the consumer price index can also be used to isolate such temporary trends by calculating an index that excludes energy prices, and 2） the present significant decline in the investment deflator is a result of the strong impact of the drop in prices triggered by technological innovation, as the IT ratio in capital investment has increased significantly, but a decline in the investment deflator triggered by such factors does not directly increase the deflation costs. Also, as previously observed with regard to supply and demand, the correlation between the GDP deflator and the GDP gap has collapsed in recent years, and it is extremely difficult to forecast these trends, so judgment of deflation based on such factors is also problematic.