Gold's main virtue is that it fights inflation. So, too, do blue chip stocks such as those found in the Dow. That accounts for most of their capital gains. According to Bill Gross of Pimco, average annual investment return on the Dow in the 20th century was 0.6% real (over inflation), a small enough term to "neglect."
The theoretical reason to own stocks rather than gold is because stocks pay dividends and gold doesn't. But Dow stocks recently carried this too far. A year ago, they were yielding only about 2% on average, no more than Treasury Inflation Protected (OTC:TIPS). That was too little compared to history. Stocks should yield more than gold because gold is a "harder" form of money.
After falling, such stocks are now yielding almost 4%. That's better than before. But historically, the Dow can be no more than five times the per-ounce price of gold, in order to be considered cheap. That would put the Dow below 5000 (versus $900-$1000 an ounce for gold), and yielding 6% On the other hand, if we kept the Dow arond 8000,using a 5 to 1 ratio would imply a price of $1,600 an ounce for gold.
One way or another, gold stands to outperform U.S.stocks during the current "gold generation" (2000-2018?).