In this paper we study time-varying coefficient (beta coefficient) models with a time trend function to characterize the nonlinear, non-stationary and trending phenomenon in time series and to explain the behavior of asset returns. The general local polynomial method is developed to estimate the...

In this paper, we present a novel sufficient dimension reduction method for multivariate regressions with categorical predictors. We adopt ideas from a previous work byChiaromonte et al. (2002) who proposed sufficient dimension reduction in regressions with categorical predictors and the work...

We propose a general dimension-reduction method that combines the ideas of likelihood, correlation, inverse regression and information theory. We do not require that the dependence be confined to particular conditional moments, nor do we place restrictions on the predictors or on the regression...

Traditional variable selection methods are model based and may suffer from possible model misspecification. On the other hand, sufficient dimension reduction provides us with a way to find sufficient dimensions without a parametric model. However, the drawback is that each reduced variable is a...

Yin and Cook (J. Roy. Statist. Soc. Ser. B Part 2 64 (2002) 159) recently introduced a new dimension reduction method for regression called Covk. Here, we develop the asymptotic distribution of the Covk test statistic for dimension under weak assumptions. This serves as an analytic counterpart...

In this article, we propose a new canonical correlation method based on information theory. This method examines potential nonlinear relationships between px1 vector Y-set and qx1 vector X-set. It finds canonical coefficient vectors a and b by maximizing a more general measure, the mutual...

In this paper we propose a dimension reduction method for estimating the directions in a multiple-index regression based on information extraction. This extends the recent work of Yin and Cook [X. Yin, R.D. Cook, Direction estimation in single-index regression, Biometrika 92 (2005) 371-384] who...