The US economy is poised for an extended period of strong growth and hiring, the chair of the Federal Reserve has said in an interview broadcast, though the coronavirus still poses some risk. Chair Jerome Powell, speaking to CBS” “60 Minutes,” also said that he doesn’t expect to raise the Fed’s benchmark interest rate, currently pegged at nearly zero, this year. And he downplayed the risk of higher inflation stemming from sharp increases in government spending and expanding budget deficits.