Treasury Secretary Janet Yellen told senators on Tuesday that the United States should return to full employment next year despite headwinds from the Delta variant and urged states and localities to speed up disbursement of emergency rental aid to families in need. Yellen made the remarks before a Senate committee on Sept. 28, in which she called the economic recovery from the pandemic “fragile but rapid.” “While our economy continues to expand and recapture a substantial share of the jobs lost during 2020, significant challenges from the Delta variant continue to suppress the speed of the recovery and present substantial barriers to a vibrant economy,” she said. “Still, I remain optimistic about the medium-term trajectory of our economy, and I expect we will return to full employment next year,” Yellen added. While the notion of full employment is not strictly defined, economists typically put the figure at somewhere between 4 …