The US dollar is a fiat currency the opposite of a commodity currency (a currency backed by a commodity like gold or silver or corndogs even). The canary in the coal mine in as far as the health of the US economy is the interest paid on T-bills, that's how much interest the gov't pays for example to sovereign wealth funds which own US Treasury Bills. It's very very low, indicating we're still in the cat birds seat. Or in other words we can pay very low interest because T-Bills are still the most trusted (i.e., secure) long term investment instruments on the planet. On the domestic front, a sign the economy is headed for trouble is when the bond market starts lighting up. That's when worried investors start moving their assets to a lower yield but a more secure refuge. At the end of the day the US economy is still the healthiest on the planet.
