John At The Center

Applying Bayesian techniques, the professors found that reversion to the mean isn’t powerful enough to overcome the growing uncertainty caused by other factors as the holding period grows. Specifically, they estimated that the volatility of stock market returns at the 30-year horizon is nearly one and a half times the volatility at the one-year horizon.

But Professor Pastor says that these methods are better suited than the standard techniques for quantifying the uncertainty faced by real-world investors. Even if Bayesian approaches have yet to become mainstream in financial research, he adds, they have become much more widely used in recent years.

via Strategies – Now the Long Run Looks Riskier, Too, for Investors – NYTimes.com.