Estimation and adaptive-to-model testing for regressions with diverging number of predictors

Abstract: The research described in this paper is motivated by model checking for parametric single-index models with diverging number of predictors. To construct a test statistic, we first study the asymptotic property of the estimators of involved parameters of interest under the null and alternative hypothesis when the dimension is divergent to infinity as the sample size goes to infinity. For the testing problem, we study an adaptive-to-model residual-marked empirical process as the basis for constructing a test statistic. By modifying the approach in the literature to suit the diverging dimension settings, we construct a martingale transformation. Under the null, local and global alternative hypothesis, the weak limits of the empirical process are derived and then the asymptotic properties of the test statistic are investigated. Simulation studies are carried out to examine the performance of the test.