Dollars problem

In dollars, this downshift in returns since the 1990s means
that a portfolio invested all in stocks would have a 8.5 percent
nominal return, which is Siegel’s 6 percent prediction for the afterinflation
return, with 2.5 percentage points of inflation added
on. It would take eight and a half years for the portfolio to double
in size. At 6.5 percent, including inflation, a much more pessimistic
assumption, the portfolio would take 11 years to double
in size.