Comprise changes in stocks occurring during the reference period at all levels between the production and the retail levels, i.e. it comprises changes in government stocks, in stocks with manufacturers, importers, exporters, other wholesale and retail merchants, transport and storage enterprises and in stocks on farms. In actual fact, however, the information available often relates only to stocks held by governments and even these are not available for a number of countries and important commodities. For this reason food balance sheets are usually prepared as an average of several years since this is believed to reduce the degree of inaccuracy contributed by the absence of information on stocks. In the absence of information on opening and closing stocks changes in stocks are also used for shifting production from the calendar year in which it is harvested to the year in which it is consumed. Cover all movements out of the country of the commodity in question during the reference period.
Remarks made above under Imports apply by analogy.
There are various ways of defining supply and, in fact, various concepts are in use. There is no doubt that production, imports and decreases in stocks are genuine supply elements. Exports and increases in stocks might, however, be considered as utilization elements. This concept is being used Feed comprises the amounts of the commodity in question and of edible commodities derived therefrom not shown separately in the balances fed to livestock during the reference period, whether domestically produced or imported. Seed comprises all amounts of the commodity in question used during the reference period for reproductive purposes, such as seed, sugar cane planted, eggs for hatching and fish for bait, whether domestically produced or imported.