Credit Card Analytics

The whole credit card industry is built around analytics in a way, from the credit scores used to evaluate risk, to the amount of credit extended. It's interesting to me to see how it is used in debt collection as well, but that makes perfect sense. I would also guess that some agents are better at collections than others and that could also be a factor in the analytics, as could staff training on how to handle collections. Can anyone else think of some other variables that might affect debt collection ability?