Various reasons for the falling $US. In a nut shell, supply and demand. There's less demand for your currency, which translates into a lower price. The world market is flooded with your dollar b/c yiz buy some much foreign stuff, particularly Chinese stuff. Yiz are bringin in way more than sending out - trade deficit. This has an up side in that it's good for the domestic market, b/c people will buy more domestic made stuff if foreing goods are more pricey. Also, a lower $US dollar should help shrink the trade defecit b/c American goods will be cheaper for foreigners to buy, thus increasing exports. As more of the $US land back in your country, the price will go up due to scarcity of the dollar abroad (scarcity creates demand - demand causes prices to increase). Currencies are constantly changing, and it usually balances out. But your gov has been borrowing a shit load, too. That gotta slow down, because puts downward pressure on the $US dollar.
I'm sure there as many theories as economists to develop them, but these are the biggies. The world's a fuct up place now, and there's more uncertainties than before. Especially with the ragheads goin' nuts, brutal exploitation of nonrenewable resources, "global warming" scare, etc. So much is based on speculation, it's not fit.
