Abstract:
We propose an Instrumental Variable method for Generalised Accelerated Failure Time (GAFT) models that adjust for possible endogeneity of the intervention of interest, without suffering the problems of the intention-to-treat method. We develop an estimatiom procedure that collapses to the linear Rank Estimation procedure for GAFT models with only exogenous variables This is accomplished by using a model that transforms the duration such that for the population parameters, this transformed duration is independent of the instrument. The estimator is used to re-analyse data from the Illinois reemploymnet Bonus experiment