Every survival analysis method I've talked about so far in this series has had one thing in common: we've only looked at one event in a customer lifetime (churn). In many cases, that's a perfectly fine way to go about things... we want our customers to stick with us, so churn is the event of interest. So why would we ever need to think about competing risks?
There's actually a critical assumption undergirding most survival analysis methods for right-censored data - that censored individuals have the same likelihood of experiencing the event of interest as individuals that never got censored. If this assumption ever gets violated, things like Kaplan-Meier estimators can become wildly inaccurate. (If you need a refresher on Kaplan-Meier curves and other concepts, take a look at my earlier post on basic survival analysis.)Continue reading