On the Performance of a Test for Coefficient of Variation

Abstract

Approximate standard errors (s.e) of sample coefficient of variation (c.v.) are available in the literature (Kendall and Stuart, 1977; Serfting 1980). Using these s.e.'s a large sample test can be constructed to test for the specified value of population c.v. The test can also be justified on the principles of Wald test. These s.e.'s have been worked out assuming that the random variable has a distribution. Following Foutz and Srivastava (1977), we study the asymptotic performance of the test when the model is incorrect. Examples from realistic situations have been considered and approximate Babadur efficiencies have been worked out. Numerical results indicate that the test is fairly robust when the departure from the model is not too pronounced.