OLABİLİRLİK ORANI YÖNTEMİNE DAYALI, YAPISAL HOMOJEN OLMAYAN VARYANS TESTLERİNİN PİYASA MODELİ İÇİN KARŞILAŞTIRILMASI

The market model of Sharpe when applied to European, U.S.A. and Japan stock markets usually results with heteroscedastic error structure. Since heteroscedasticity in error terms cause inefficient parameter estimation, it should be tested before data analysis. The objective of this paper is to present five widely used likelihood based constructive heteroscedasticity tests which are  the ordinary likelihood ratio test, the conditional likelihood ratio test, the corrected modified likelihood ratio test, the modified likelihood ratio test, the profile likelihood ratio test and the residual likelihood ratio test. Also simulation study is performed to compare these tests.