Such comparisons can be made over time, or the value added by one entity can be compared to others as a gauge of relative importance in the same time period. The scope of interest must be clearly defined, since it will affect value added calculations. Gross and net value added can be computed for all the goods produced and sold by an industry, or they can be computed on a per unit basis. On-farm value added can be found from farm cost of production data. Off-farm measurements usually emphasize forward linkages after the farmgate.
Gross value added measures include the aggregate marketing bill and per unit price spreads.
Off-farm figures are often broken down by marketing function such as processing and transportation, and wholesaling. Other common breakdowns are gross value added by input cost category, and the shares of net value added contributed by different factors of production. Stuart Nakamoto is a member of the Western Extension Marketing Committee and is an Extension Economist at the University of Hawaii at Manoa.