Searching for Lost Decades in U.S and Global Equities

This paper estimates the probability of a “lost decade” where equity investments lose value over a ten year period. The findings are a reminder that equity investments are risky even over longer time periods, and investors should take this into consideration when making portfolio choices. It also introduces a simple method to allow the reader to combine beliefs about long run stock returns along with computer simulated return distributions. Finally, the results for the U.S. are augmented with international data which strengthen the case for long horizon risk.