And I also -
Free markets determine gold's price. If currencies were 100% backed by metals, yes, fixed to gold by fiat, say at the old $20/oz, and our trading partners did likewise keeping their 100% backed currencies at a fixed percentage of gold, fluctuations in the gold price WOULD NOT AFFECT exchange rates BETWEEN currencies. Only one's confidence in another's Govt and economy would, as free markets allow.
There would be no inflation - for govt printing is the only source of that.
No other system entrusted to corruptible men is capable of preventing unlimited Govt from rolling the presses in it's own interest. Our current situation.
uh...well, that's debatable. And, certainly, if it were true under the gold/dollar peg, then "free markets" -- defacto -- determined the dollar's price. But that wasn't possible, because gold's price was fixed by fiat, which was when money was truly "fiat." Now, money value is determined by the market.
The gold standard was an artifice; it was training wheels. The training wheels have to come off as the child grows. Hopefully, the child grows with enough character to handle a real bicycle.