Until quite recently, Robert Litan was a nonresident senior fellow in the Economic Studies Program at the Brookings Institution, a bipartisan Washington think tank with a sterling reputation. The Institution’s website describes him thus: ”a widely recognized expert in regulation, antitrust, finance, among other policy subjects.” But he is no longer a fellow there, because he had the misfortune to disagree with Senator Elizabeth Warren. No Proper Risk Assessment The subject of the criticism, as it happens, was financial regulation, specifically new rules proposed by the Department of Labor (and supported by Senator Warren) that would impose fiduciary obligations on brokers and financial advisors who provide advice for IRAs. A fiduciary obligation, of course, would be a big step up from the present level of obligation under SEC authority. The latter holds merely that those recommendations must be “suitable” for investors, judging suitability by income, ass...