Cass R. Sunstein '75 will return to Harvard Law School in August after a three-year stint as President Barack Obama's regulatory chief, White House and Law School officials announced Friday.

Sunstein, who has directed the Office of Information and Regulatory Affairs (OIRA) since 2009, will return to teach at the Law School and to head the new Program on Behavioral Economics and Public Policy. A White House announcement Friday said that with a newborn child and the fall semester approaching, Sunstein had made the decision to return to teaching and step down as regulatory czar just months shy of November's presidential election.

"Working for the Obama Administration has been an extraordinary honor,” Sunstein said in a statement through the Law School. “I am thrilled to be rejoining the Harvard faculty and to have the opportunity to work with the countless sensational teachers and students who are there.

The President and White House staff praised the outgoing czar on Friday, citing the government-wide regulatory "look-back" he led and the billions of dollars in savings it generated. During his time at OIRA, Sunstein is credited with creating some $91 billion in economic benefits by enacting new regulatory measures and making existing ones more efficient.

"Cass has shepherded our review of existing rules to get rid of those that cost too much or no longer make sense, an effort that is already on track to save billions of dollars," Obama said Friday in a statement. "With these reforms and his tenacious promotion of cost-benefit analysis, his efforts will benefit Americans for years to come."

Law School Dean L. Martha Minow lauded Sunstein, calling him one of the top legal minds at work today.

"With Cass’s passion for figuring out what works, what doesn’t, and why, he infused his government service with an acute awareness of human behavior and motivation. It is our tremendous good fortune that he will now bring the lessons and insights from his extraordinary experience in government to the Law School and to the wider university," Minow said in a statement.

Sunstein's tenure in Washington was not without controversy, as his office oversaw reform of regulation surrounding the financial services industry and various environmental rules. In a politically charged climate, Republicans felt Sunstein reached too far, while Democrats felt he too often folded to business and other Republican interests.

Sunstein and Obama became friends when both were faculty members of the law school at the University of Chicago in the 1990s, and it became clear after Obama's election in 2008 that Sunstein would have a job of his choosing in Washington. In 2009, he was a part of a small exodus of Harvard professors, who followed Obama, a former Law School student, to the capitol to fill key top positions in the administration’s early days.

When he returns to the Law School this fall, Sunstein will refill the position he left some three years ago as well as fill a new one in the Program of Behavioral Economics and Public Policy. Law School administrators could not be reached for immediate comment regarding the new program.

But one certain change from Sunstein's first time around: his wife, former Harvard Kennedy School professor Samantha Power, will not be on the faculty with her husband, but in Washington, where she will remain a member of the National Security Council.

—Staff writer Nicholas P. Fandos can be reached at nicholasfandos@college.harvard.edu.