That is, I have data on my dependent variable and the covariates at the end of every year. I have many ties some of the years. My concern mainly relates to the way of handling this grouped version of the Cox proportional hazards model. On the one hand I do not want to use the logistic approximation of the model, but the true Cox model. I should use for handling ties.
Suggestions are welcome.
Thanks a lot. Department of Economics and Management. University of Zaragoza.