fixed-base index

fixed-base index

[¦fikst ¦bās ′in‚deks]
(statistics)
In a time series, an index number whose base period for computing the index number is constant throughout the lifetime of the index.
References in periodicals archive ?
A fixed-base index works best over relatively short periods, however, because the composition of products can change significantly over time.
The first -- a fixed-base index -- compares each week in 1993 to the modal price in 1992, using as weights the average 1992 sales at the modal price.
Given this long-term price relative, a fixed-base index is obtained by aggregating over cells using the formulas in exhibit 1.