"The labor market is showing signs of cracking," Heather Long, Navy Federal Credit Union senior economist, wrote Thursday. "It's not a red siren alarm yet, but the signs keep growing that businesses are starting to cut workers." The latest data tees up an August jobs report that, when released Friday morning, is expected to show another month of tepid job gains. Economists have forecast that the economy added 80,000 jobs last month, which would be a slight increase from the slower-than-expected 73,000 net gain in July.