Merrill Lynch economist David Rosenberg, one of the most bearish Wall Street economists, says to look past the 1990-91 recession as a guide to the current downturn. The key difference: the depth of home-price declines.

Mr. Rosenberg says in a note to clients that the current downturn is hitting more broadly than the credit crunch and real estate meltdown in the 1990-91 recession, which lasted eight months (as did the mild 2001 contraction)

Home prices today are falling in 85% of the country vs. 40% during that period, he notes.

Mr. Rosenberg, who was among the first economists to forecast a 2008 recession. He sees average prices nationwide dropping 20% to 30% more, on top of the 11% decline since the 2006 peak.

The mid-1970s recession “not only saw a sharp and sustained rise in food and energy prices, as is the case today, but also saw a very similar consumer balance sheet squeeze from a simultaneous deflation in residential real estate and equity assets