I have a group of customers that received a offer at time t0 (start_date). The offer lasts for 6 months until t1 (end_date). I further have a variable that records the date (if) the customers defects (defection_date). I want to study whether the defection rate increases after the offer is not valid anymore. I also have a controlgroup that did not receive the offer, so I would like to compare the defection rate in the controlgroup against time between t0 and t1 and time > t1
Example of data,
id start_date end_date defection_date controlgroup
1 1Jan2008 1July2008 . 1
2 5Jan2008 5July2008 20feb2008 0
3 10Jan2008 10July2008 20July2008 0
4 15Jan2008 15July2008 . 0
At first I thought that I might compare mean defection rate when offer valid against when offer is not valid anymore. However, I have been browsing through some of the post done on survival curves/survival analysis. Now I am uncertain whether I should give that a try? Any comments is much appreciated.
Thanks for your consideration.
Also, I am using Stata 10.
Best wishes,
Alexander Severinsen
*
* For searches and help try:
* http://www.stata.com/help.cgi?search
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/
