With two weeks to go in 2009, the declines since the end of 1999 make the last 10 years the worst calendar decade for stocks going back to the 1820s, when reliable stock market records begin, according to data compiled by Yale University finance professor William Goetzmann. He estimates it would take a 3.6% rise between now and year end for the decade to come in better than the 0.2% decline suffered by stocks during the Depression years of the 1930s.
Since the end of 1999, the Standard & Poor's 500-stock index has lost an average of 3.3% a year on an inflation-adjusted basis, compared with a 1.8% average annual gain during the 1930s when deflation afflicted the economy, according to data compiled by Charles Jones, finance professor at North Carolina State University. His data use dividend estimates for 2009 and the consumer price index for the 12 months through November.
Just shows how fickle conventional wisdom is. The 1990's had its best return decade ever, averaging 17.6% returns, and the equity return premium was often estimated around 6%. Now, it's generally thought to be around 2-3%.