Should we return to the gold standard?

— -- Talking about the monetary system these days requires using unimaginably large numbers, such as $1 trillion, the total U.S. currency in circulation, and $10.9 trillion, the U.S. government debt held by the public.

The growing U.S. debt — $15.6 trillion, if you throw in Social Security and Medicare — is one reason people fear inflation and think that the monetary system is out of control. "Never in history have we run debts and deficits to this magnitude," says Lance Roberts, chief economist at StreetTalk Advisors. "We've never been here before."

It's one reason the gold standard is gaining renewed popularity. Rep. Ron Paul, Republican candidate for president, has long advocated a role for gold in monetary policy. Jim Grant, the erudite editor of Grant's Interest Rate Observer, has long made the case for returning to the gold standard. In layman's terms, the gold standard means hitching the value of the dollar to the price of gold. The amount of gold the country owns limits the amount of money it can print.

But returning to the gold standard also has myriad problems. On a practical level, there's not enough gold in the world to return to a gold standard — and no one else in the world is on the gold standard. By tying the value of the dollar to gold, the government cedes control of monetary policy, making it unable to increase the money supply in times of economic crisis.

The U.S. tied the value of the dollar to the price of gold until 1971, when then-president Richard Nixon dismantled the last vestiges of the gold standard. But the gold standard had effectively ended for most people in 1933, when the government decided that individuals could no longer redeem dollars for gold.

What's the allure of the gold standard? "Its prime attraction is to apply a measure of monetary discipline," says Ian McAvity, editor of Deliberations on World Markets, a newsletter. When you tie your currency to gold, there's only so much currency you can issue — because there's only so much gold. In theory, at least, tying the value of the dollar to gold would prevent the government from printing too much money and creating runaway inflation.

Gold has been recognized as money since the Lydians first started making coins, sometime around 700 B.C. It's portable, and doesn't rust. "Drop a gold coin on any street in the world, and people will pick it up and think of it as money," McAvity says.

But one of the things that creates gold's value — its rarity — also argues against using it to back the nation's currency.

Most of the gold that has ever been mined is still around, according to the World Gold Council. Your wedding ring could once have been part of Cleopatra's earrings. There are about 170,000 metric tons of gold in the world, according to the Council. That would create a cube 67 feet on each side. Melted on an NFL football field, sideline to sideline and endzone to endzone, all the world's gold would rise 5.4 feet.

All the gold in the world — 170,000 metric tons — translates into about 5.5 billion troy ounces. (Troy ounces are 1.1 ounces.) All that gold would be worth roughly $9 trillion at $1,639.10 an ounce.