Total single-family originations could drop another 20 percent or more in 2012, following a similar decline this year, according to mortgage industry economists. The consensus forecast from Fannie Mae, Freddie Mac and the Mortgage Bankers Association is that $1.28 trillion in home loans will be originated in 2011, a decline of 22 percent from last year’s estimated volume. But 2011 will prove to be just a prelude to another sharp decline in production next year. Despite the fact that mortgage rates are expected to stay at...