Seminar Notice

Statistical Laboratory
Iowa State University
 
DATE AND TIME: Monday, October 3, 2005, 4:10 p.m.
 
PLACE: 319 Snedecor
 
SPEAKER: Jean Opsomer, Department of Statistics, Iowa State University
 
TITLE: Nonparametric Models and Nonresponse Adjustments in Surveys
 
 
Nonresponse is a common problem in surveys, which can lead to biased estimators and erroneous inference if it is not accounted for in the estimation procedures.  Because the nonresponse mechanism is typically unknown, nonparametric specification of this mechanism is attractive because of its generality and robustness.  We will address two issues related to nonresponse.  First, we evaluate the robustness of the commonly used "weighting cell estimator" to misspecification of the cells, by assuming a nonparametric response probability mechanism.  We show that the weighting cell estimator remains consistent even under cell misspecification.  Second, we develop a new response-weighted estimator that relies on a nonparametrically estimated response probability function. The theoretical properties of the new estimator are derived, and a replication-based variance estimator is proposed.
 
This is joint work with Damiao da Silva.
 
COFFEE:  3:45 p.m., 104 Snedecor Hall
 
Seminar schedules and abstracts are available via WWW:  http://www.stat.iastate.edu/

Jeanette La Grange
Department of Statistics
102 Snedecor
Iowa State University
Ames, IA  50010-1210
515 294-3440 (office)
515 294-4040 (fax)
http://www.stat.iastate.edu/directory/staff/jeanette.html