We've experienced an "inverted yield curve," say economists. Last year, the Federal Reserve kept ratcheting up short-term interest rates in an effort to slow what they thought was a too hot economy. This year, they've reversed course and are lowering rates. Cuts by the Federal Reserve primarily affect short-term interest rates, which also influence the rate on adjustables, explains [Doug Duncan]. Now, mortgage borrowers are in the enviable position of choosing from relatively low-priced, fixed-rate loans as well as from ajustables with an even lower starting rate.