Earlier quoted context omitted.
Using the adjusted close assumes that you put your dividend receipts into a mattress so it's still slightly low, but I doubt that's more than .1% or .2% for a typical portfolio over a moderate timeframe. I wholeheartedly agree with you that it's dangerous to bet your retirement on a level of return that many won't achieve.
Actually, can you explain that more? Since yahoo adjusted close says it takes dividends into account, I took that to be the same as immediately reinvesting your dividends in the same holding. You're saying that instead, it's the same as issuing the dividends as cash and then forgetting about it? If so, then how do people actually backtest long term holdings to assume reinvested dividends? As far as free historical da…
My apologies for the confusion.