( November 13, 2014) -- Anti-cartel enforcement is robust and effective, but oddly dependent on only a few narrow sources of information. It relies on its ability to persuade members of the cartel itself to cooperate and give evidence, through incentives such as the Department of Justice leniency program. This approach has yielded good results in some areas, but also contains puzzling holes where certain industries are not targeted, perhaps because the members of those industries are too tough to be so easily turned. The antitrust agencies have been gaining experience with alternative paths of investigation, however. It may now be time to look for more use of those....