U.S. business leaders have turned pessimistic, according to Grant Thornton LLP’s most recent Business Optimism Index, a quarterly survey of U.S. business leaders. Only 45% believe the U.S. economy will improve in the next six months (down from 64% three months earlier), 40% plan to increase staff (down from 49%), while 12% plan to decrease staff (up from 10%) The Index itself is down 7.1 points to 62.6.