The increase is “a signal of some fundamental, underlying strength in private companies that is really not being registered anywhere else,” PayNet founder Bill Phelan said. Such signs are exactly what Fed officials have been waiting for, as they gauge the right time to lift short-term borrowing costs from near zero, where they have been for 6-1/2 years. The small-business borrowing index has historically tracked ahead of U.S. gross domestic product growth by two to five months, and is a good predictor of capital spending and job growth, Phelan said.