"[W]hile they state their dataset includes 3500 plans, ... nowhere in the heavily footnoted (138 in all) does it explain the source of this data.... [T]he paper also makes the identical mistake [made in a PBS Frontline story entitled 'The Retirement Gamble'] by digressing into the notorious 'passive versus active' debate.... [T]he two law professors seem to have their own sort of naive sense when it comes to the DOL's strategy on 401k fees.... DOL cares only about reasonable costs and not low cost, which is a huge difference since the DOL allows plan sponsors to pay more in fees if they are getting something more in service."