Small businesses in the United States borrowed more money during August, a survey showed Monday, signaling that business owners are becoming more confident in the economy. PayNet, a research firm that tracks loans to small businesses, said that lending rose 3 percent, marking the second straight monthly increase. The Thomson Reuters PayNet Small Business Index rose to 109.9 from 106 in July. PayNet bases its index on new commercial loans and leases granted to small businesses by U.S. lenders.