The prices are used in calculating PPI under the stage of processing have obtained to a large
extent from the first commercial transaction prices. These representative prices are taken from the
producers, central markets, local markets, trade associations as well as from other government
agencies.
In 1999, the Producer Price Index calculation has been improved the listing, weight, and
base year from 1985 to 1995 by using the input-output table conducted by the Office of the National
Economic and Social Development Board. The former Wholesale Price Index has been renamed as
the new Producer Price Index for Thailand under the classification of products by activities (CPA) in
order to compare with the international classification. The price used in the PPI calculation are at
producer level or nearly.
