Mr. Sum said he had no bones with Mr. Romney touting the role he played at Bain Capital creating jobs — more than 100,000 by the ex-governor's own count.
"The fact the unemployment rate went down had nothing to do with the policies of his administration," said professor Andrew M. Sum, director of the center for labor market studies at Northeastern University in Boston. "We had one of the three worst job-creation rates in the country under his administration. The unemployment rate largely went down for one reason, because people withdrew from the labor force and left the state."