From the original paper the key argument is: > Our estimation relies on a coverage assumption: a system will face serious delays or will be likely discontinued

From the original paper the key argument is: > Our estimation relies on a coverage assumption: a system will face serious delays or will be likely discontinued if its current set of authors covers less than 50% of the current set of files in the system An author of a file is defined as a user who has made significant (based on pre-calculated weights) contributions to a file