Cass Sunstein ushered in the end of an era when he announced on Friday that he would leave the White House as overseer of federal regulation.  In his wake, Mr. Sunstein, 57, leaves an impression, much of it garnered by his application of a cost-benefit analysis to his reviews of proposed rules. As administrator of the White House Office of Information and Regulatory Affairs (OIRA), Mr. Sunstein:

• Reviewed the rules implementing President Obama’s health care act and the Dodd-Frank financial regulatory reform law
• Backed major environmental initiatives, including higher fuel efficiency standards for cars and trucks and new toxic emissions rules for power plants
• Approved the revamping of the decades-old food pyramid (it is now a "plate"), the tightening of salmonella rules for eggs and a crackdown on prison rape
• Midwifed a deal between appliance manufacturers and the Department of Energy to make refrigerators more energy efficient

Mr. Sunstein fit in well.  He was a close friend of President Obama’s from their days on the University of Chicago Law School faculty.  Among the high-profile positions available to him, he chose OIRA (pronounced "oh, Ira"), a unit of the White House Office of Management and Budget that reviews every regulation proposed by an executive branch agency.

• Of the hundreds of regulations issued by the administration as of late last year, three-quarters were changed at OIRA, often at the urging of corporate interests, according to an analysis from the Center for Progressive Reform, a liberal-leaning group that monitors federal regulation.
• For rules from the Environmental Protection Agency, the figure was closer to 80%, the group found. In virtually every case, the rule was weakened, the group claimed.
• Mr. Obama credited Mr. Sunstein with introducing a regulatory system that protected Americans while eliminating "tens of millions of hours of paperwork burdens" for businesses and citizens.

Critics denounced his influence:

• "Cass Sunstein is the most well-connected and smartest guy who’s ever held the job.  But he’s also done untold damage." -- Rena Steinzor, president of the Center for Progressive Reform and a professor at the University of Maryland Carey School of Law.
• Professor Steinzor cited Mr. Sunstein’s role in the killing of the E.P.A.’s proposed tightening of the standard for ozone pollution, the indefinite delay of rules governing coal ash disposal and the withdrawal earlier this year of a proposed update of child agricultural labor standards.

Why is He Leaving? No explanation has been provided by the White House which offered no explanation for the timing of Mr. Sunstein’s departure.  Of his time at OIRA, Mr. Sunstein claimed the economic benefits of the regulations he has vetted, saying the net benefits have exceeded $91 billion, exceeded the benefits of rules issued by previous administrations. Since the announcement, he has declined to comment. At Harvard, he will direct the new Program on Behavioral Economics and Public Policy.  The White House said Boris Bershteyn, the budget office’s general counsel, will serve as interim regulatory chief.  His presence at the White House will live on in his wife, Samantha Power, who will return to her post as a senior director for multilateral affairs and human rights  after a maternity leave. For further details, go to [NY Times, 8/3/12].