A statistic which assigns a single number to several individual statistics in order to quantify trends. The best-known index in the United States is the consumer price index, which gives a sort of ``average'' value for inflation based on the price changes for a group of selected products.
Let be the price per unit in period , be the quantity produced in period , and be the value of the units. Let be the estimated relative importance of a product. There are several types of indices defined, among them those listed in the following table.
Index | Abbr. | Formula |
Bowley Index | ||
Fisher Index | ||
Geometric Mean Index | ||
Harmonic Mean Index | ||
Laspeyres' Index | ||
Marshall-Edgeworth Index | ||
Mitchell Index | ||
Paasche's Index | ||
Walsh Index |
See also Bowley Index, Fisher Index, Geometric Mean Index, Harmonic Mean Index, Laspeyres' Index, Marshall-Edgeworth Index, Mitchell Index, Paasche's Index, Residue Index, Walsh Index
References
Fisher, I. The Making of Index Numbers: A Study of Their Varieties, Tests and Reliability, 3rd ed.
New York: Augustus M. Kelly, 1967.
Kenney, J. F. and Keeping, E. S. ``Index Numbers.'' Ch. 5 in
Mathematics of Statistics, Pt. 1, 3rd ed. Princeton, NJ: Van Nostrand, pp. 64-74, 1962.
Mudgett, B. D. Index Numbers. New York: Wiley, 1951.