1.Center for Applied Statistics, School of Statistics, Renmin University of China, Beijing 100872; 2.Center for Applied Statistics, School of Statistics, Renmin University of China, Beijing 100872;School of Statistics, Lanzhou University of Finance and Economics, Lanzhou 730101
In the analysis and modelling of statistical data, variation and volatility of which are becoming more concerned. Thus, it is crucial to effectively detect and
exactly estimate this variation. In this paper, a linear heteroscedastic model is mainly considered. The aim is to recover the unknown scale function robustly. As is known, interquartile range is a robust estimator in classical estimation of scale parameter. Based on this, “minimal interquartile range” and “optimal quantile range” estima- tors are proposed to effectively estimate the scale parameter of unknown probability distribution F. Besides, in order to obtain the scale function of a linear heteroscedastic model, we generalize this idea to conditional distribution and apply quantile regression techniques simultaneously. It is worth noting that information of mean regression function is not required in estimation, which makes the proposed approach superior.
In addition, asymptotic properties of proposed estimators are studied and compar- isons with classical interquartile range are made. The results show that our proposed estimators perform etter under both symmetric and asymmetric distributions. In the end, simulations are conducted to examine the performance of our methods.
XIONG Wei, TIAN Maozai.
ROBUST ESTIMATORS OF SCALE FUNCTION. Journal of Systems Science and Mathematical Sciences, 2014, 34(6): 703-717 https://doi.org/10.12341/jssms12352