Summary
The introductory part of the paper discusses the implications underlying the use of infinite series expansions for determining expected value and variance of ratios of discrete variates. The basic initial step in deriving such expected values and variances, without, the use of infinite series expansions, lies in the establishment of an identity by the simple division of unity by a binomial expression which is a linear function of the random variable in the denominator of the ratio. The method leads to exact expressions. Some applications are considered.
Similar content being viewed by others
References
Fieller, E. C.: The distribution of the index in a normal bivariate population. Biometrika24, 428–440, 1932.
Goodman, L. A. andH. O. Hartley: The precision of unbiased ratio-type estimators. J. Amer. Statist. Assoc.53, 491–509, 1958.
Hartley, H. O. andA. Ross: Unbiased ratio estimators. Nature174, 270–271, 1954.
Koop, C. J.: A note on the bias of the ratio estimate. Bull. Inst. Int. Statist.33, 141–146, 1951.
—: On upper limits to the difference in bias between two ratio estimators. Metrika5, 145–149, 1962.
— On an identity for the variance of a ratio of two random variables. J. Roy. Statist. Soc. Ser. B26, 484–486, 1964.
— An exercise in ratio estimation. The American Statistician22(1), 29–30, 1968.
Merill, A. S.: Frequency distribution of an index when both, the components follow the normal law. Biometrika20 A, 53–63, 1928.
Midzuno, H.: An outline of the theory of sampling systems. Ann. Inst. Statist. Math.1, 149–156, 1950.
Pearson, K.: Mathematical contributions to the theory of evolution—On a form of spurious correlation which may arise when indices are used in the measurement of organs. Proc. Roy. Soc. (London)60, 489–497, 1897.
Stefan, F. F.: The expected value and variance of the reciprocal and other negative powers of a positive Bernoullian variate. Ann. Math. Statist.16, 50–61, 1945.
Sukhatme, P. V.: Sampling Theory of Surveys with Applications. New Delhi, Indian Society of Agricultural Statistics, and Ames, Iowa State College Press, 1953.
Tin, M.: Comparison of some ratio estimators. J. Amer. Statist. Assoc.,60, 294–307, 1965.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Koop, J.C. On the derivation of expected value and variance of ratios without the use of infinite series expansions. Metrika 19, 156–170 (1972). https://doi.org/10.1007/BF01893291
Issue Date:
DOI: https://doi.org/10.1007/BF01893291