from the report, as quoted above, my emphasis;
On the negative side of the ledger, airlines continue to overbook peak times at the most popular airports, despite the FAA’s effort to control the problem, and the government doesn’t have a good grasp on other structural reasons for delays, the inspector general said, pointing to more data that should be collected.
Ahh, the wonders of 'light touch regulation'. When the end users and the govt still want to control the system as if it was the old days...
Time to collect more data, make more reports and then head for the golf course with a job well done.