The article accounts for inflation. If you don't do that and you take an average over the entire history of the S&P500 then you get returns of 9.0% annually. Th

The article accounts for inflation. If you don't do that and you take an average over the entire history of the S&P500 then you get returns of 9.0% annually. That's not so far off from 10%. Not accounting for inflation is fair enough in Dave Ramsey's case since he's all about tying to get people to invest more. Since people's cash is going to be hit just as hard by inflation as stocks it isn't necessary to account for it.