NEW YORK - November 19, 2009 - If you already took advantage of the government’s tax credit for first-time homebuyers - or are planning to do it anytime soon - you should know that sales of existing homes are expected to peak in the final quarter of 2009, then begin a year-long slide, which is likely to be a sharp one, according to some estimates.

“Most of it [the tax credit] is simply shifting sales from one period to another,” says Global Insight economist Patrick Newport. “It doesn’t get rid of the fundamental problem; there's still a glut of houses.”

Newport, for instance, expects single-family home sales to hit an annual rate of 5.88 million units in the fourth quarter (vs. 5.30 million in the third quarter). Thereafter, sales will fall to 5.65 million in the first quarter and average just 4.75 million in the second half of the year.

“We expect a little stall in 2010,” says David Crowe, chief economist at the National Association of Home Builders.