Sections 1 and 2 discuss the construction of the aggregate outputs and inputs using the Laspeyres and Paasche formulae respectively, while Section 3 uses the Fisher (1922) ideal index number
formula to aggregate inputs and outputs.
There is also, as some economist pointed out, the problem that an overall output ratio, be it average or marginal, means little, unless one is able to obtain an ideal index number
which is satisfactory for aggregating both real capital and final outputs.
For example, [I.sub.87,88] is a Fisher Ideal index number
computed as the geometric mean of two indexes measuring price change between 1987 and 1988; the first uses weights from 1987 and the second, weights from 1988.
Other weighting alternatives.-BEA is experimenting with the Fisher ideal index number
formula and with derivatives of it.