Do you know what the variance is on (1+-.01)²⁵⁰ because that's the stock market. It's not 1.0001²⁵⁰ it's not 1.006^12. You can't use that math with a variance. The compounding isn't consistently greater than one. Some days you lose, and that simple fact means the compounding arguments don't work. You can't assume you'll have Pe^(1.08n) after n years. You might well have less than P, and that means you're way way behind for all future years. If you're relying on compounding you can't just draw a line over a ten year period and say "oh well accounting for inflation this goes up 8% every year so we'll set our compounding rate at 1.08." That's not the way the math works.