How do collection agencies decide which borrowers to sue?

There are costs associated with bringing a civil lawsuit and collection agencies want to be sure of the following:

* There is a good chance that the collection agency will win

* The amount of money is significant - not small claims

* All attempts to collect (legally via FDCPA) have been met with a lack of payment

If the collection agency has one or more attorneys on staff, they will be more likely to pursue borrowers in court as the expense to do so is lower with in-house counsel vs. retained counsel.