Bloomberg's Eric Martin and Michael Tsang have a good story on the big difference between economists and stock market analysts over 2010's growth forecasts:

Never before have Wall Street stock analysts diverged more with economists at their own firms over the outlook for earnings in the Standard & Poor’s 500 Index.

Profits for companies in the S&P 500 will rise 25 percent next year, according to the average estimate of more than 1,500 equity analysts tracked by Bloomberg. That’s 10.9 times faster than the expansion in gross domestic product foreseen by 53 economists surveyed last month. The ratio of income to GDP growth is the highest on record and compares with an average of 6.1, based on data compiled by Bloomberg going back 60 years.

Looking at historical relationships, Martin and Tsang say that the economy would have to grow 4.1 percent in order for this to come to fruition. The current forecast is for 2.3 percent growth. With consumer spending expected to remain depressed next year, analysts are looking overseas for the demand needed to juice profits.

Based on recent optimistic IMF forecasts, this isn't out of the question. Martin and Tsang also write that 1993 was the last time that earnings grew 10 times faster than GDP. Using real GDP data from the BEA and real earnings for the S&P from Robert Shiller, I get different numbers than Martin and Tsang: In Dec. 2003, year-over-year growth of earnings was 29.4 times greater than GDP growth (74% versus 2.5%).

Either way, such a gap may just be a sign of an economy coming out of a recession. But maybe more importantly, the divergent surveys show once again that while the stock market is part of the economy, it's not all of it.