On sufficient dimension reduction with missing responses through estimating equations

A linearity condition is required for all the existing sufficient dimension reduction methods that deal with missing data. To remove the linearity condition, two new estimating equation procedures are proposed to handle missing response in sufficient dimension reduction: the complete-case estimating equation approach and the inverse probability weighted estimating equation approach. The superb finite sample performances of the new estimators are demonstrated through extensive numerical studies as well as analysis of a HIV clinical trial data.