Brian Sack was named Markets Director at the Federal Reserve Bank of New York on June 3, 2009. He resigned from his position in April 2012, and will leave in September. He will remain in his current role as executive vice-president of the markets group and manager of the system open market account for the Federal Open Market Committee, until June 2012, when the Fed's "Operation Twist" program ends. 
Sack was one of the intellectual architects of "Operation Twist", in which the Fed bought longer term bonds in an effort to force down interest rates. He will act as an adviser until he leaves in September.
He is currently a vice president at Macroeconomic Advisers, LLC, an economic analysis firm based in St. Louis and Washington. Before joining that company in 2004, Sack was head of the Monetary and Financial Markets Analysis section of the Federal Reserve's Board of Governors.
Sack received a Ph.D. in economics from the Massachusetts Institute of Technology in 1997 and a B.A. in mathematics and economics from the University of Vermont in 1992.