ESTIMATION OF RATE AND MEAN FUNCTIONS FROM TRUNCATED RECURRENT EVENT DATA

This article investigates data on recurrent events that arise from sou rces such as warranty claims, where the observation period for a unit is unknown until it experiences at least one event. This creates a typ e of truncation in the data. We consider nonparametric estimation of m eans and rates of the event occurrences with such ''zero-truncated'' d ata and examine the case where the population size and the distributio n of observation times across units are at least approximately known. We study the behaviors of the proposed estimators by simulation. We ex amine some car warranty data by applying the methodology developed her e and considering the underlying assumptions.