Weakening the Fed's supervision could lead to the build-up of "real risks" in the banking system that could build up over time or threaten a crisis, warns Mr. Barr, the Fed governor. Mr. Barr said supervision depended on a solid rating framework, forward-looking regulation and skilled staff. He added that measures such as "shrinking the scope of reviewers, weakening the rating system and redefining the'unsafe and unsound 'business standards that the banking industry has long followed" would make...