Economists polled by The Wall Street Journal see new-home sales in April bouncing back to 420,000 when the data are released Friday. The homeownership rate has dropped considerably from its prerecession peak, affected by foreclosures, unemployment and tightened lending standards. For the homeownership rate to stabilize and sales to approach their historical pace, price gains may have to slow. Pushing mortgage rates down again could keep sales and prices rising sharply in tandem.