Since 1947, the ratio of US GDP to US currency in circulation has ranged from under 9 to over 26 (rising steadily from the low in 1947 to the high in about 1981, and then steadily down to the current approximate 16.5). The average is 20.He doesn't conclude that gold is toppy, but he does suggest that it's not undervalued by this "real money" metric. (I should note that currency in circulation is a lot smaller than M1, which is the money estimate used to get the $5,000/oz figure.)
We don’t have data for that ratio for other countries, but let’s assume that globally it is about the same (9 to 26, average 20, currently 16.5).
So, at nice round multiples of 10, 15, 20 and 25, this is how much currency may be in the world at this time: $7.0, $4.7, $3.5 or $2.8 Trillion at USD purchasing power parity.
If there are 5.3 billion Troy ounces above ground, then if all currency were replaced by all above ground gold (including jewelry) and if the 1.6 billion Troy ounces of “proven” reserves below ground are not part of the calculation, the value of gold to replace all of the currency in the world might range from about $500 per ounce to $2,700 per ounce.
On the other hand, there's Moses Kim. He looks at charts for both gold and the Amex Gold BUGS Index (HUI) in terms of the Standard and Poor's 500. Kim allows that the S&P is doing better in recent weeks, but he concludes that the gold stocks are in a consolidation pattern. As for gold, he's still bullish for national debt reasons.
People keep on waiting for the gold bubble to pop, but I think the government debt bubble is far more likely to pop first. As long as our government doesn't impose discipline on their finances, gold will find strong fundamental support.
The two make for a bit of a mixed bag. What struck me about both is that they're both reasonable: no super-bullishness on one side and pooh-poohing on the other.