The Yuan will not overtake the dollar as long as China keeps the exchange market controlled in order to favour their exports. But, even so, exchange rates don't really mean anything alone- the value of the Euro has been
dropping as Europe was recovering (from $1.50 to just under $1.10), which was good as it helped European exports and was affordable thanks to the collapse in oil prices; in fact, these past weeks, fears of turbulence in the Eurozone have cause the value of the Euro to
go UP, gaining some cents on the dollar to $1.13. This is to say, the value of the Yuan can go up or down or sideways and that will mean different things depending on how every other variable goes. If, suddenly, the Yuan goes to parity with the dollar, that would essentially cause the entire Chinese export industry to go out of business in a matter of days, unless prices collapsed all over China, which would imply an implosion in the Chinese economy, or the US had an absurd hyperinflation that can't possibly happen without a civil war breaking out in the US or, idk, a volcano blowing up half the country or something.
In fact, the world economy is taking a step back these days because of a cooldown in the Chinese economy, sending a chilling blow to the US, and the Greek Elephant in the European Room, which (I hope!) will be kicked down the road for a few more months next week. I still hope my grandchildren will see it fixed, although I wouldn't bet on it.
It has to do with how heavily the US government is in debt, with trillions owed, and that many are receiving government subsidies.
The US is in danger... because their tax revenue isn't high enough. The US owes trillions, alright, but those trillions mean just 3/4 of the total size of the US economy. The US can afford to owe trillions because every year they make even more trillions. Of course, the Government doesn't raise enough tax money to use that proportion (because it doesn't really matter how much money the entire country makes if the Government only gets a small portion of about 30%). Still, it's manageable, as the interest rate is hilariously small, likely to be beaten by inflation in the long run. Either way, the solution is a matter of ideology. You can argue that the Government should raise more tax money so it can afford all those services, as it happens in Europe (where most countries can even afford to run a public health system!), or you can argue that the solution is taking away those subsides and leaving a bare-bones State and hoping that poor people will get random charity instead of stable Government subsidies to be able to eat, and that private companies will run everything more efficiently (an argument that any Londoner will tell you from experience doesn't work for health and transport- but chances are even the English Conservatives would be "liberals" in the US). But that is a completely ideological issue- a country can pay their bills by having with a bigger Government that takes more taxes, or you can close the Government and have no bills to pay and let everybody live in a wild jungle. The solution is somewhere in between, the question is where, and it will depend on the ideology of the person answering.
They're saying that the US dollar will lose its value and there will be no currency to provide, and telling us that we should stock up on supplies before this happens. I'm not gonna provide links, but you can Google it and find out different things on what have to be said. I heard rumblings about it earlier in the year, but yesterday I saw another commercial about it, and it looks like it's nearing sooner than we thought.
A currency can "lose value" without anything at all happening in a country. Yesteryear a US citizen would make $4000 a year and a burger would cost 20c. Now that same dude will make $40,000 [actually more, income after inflation has actually gone up in the last 50 years, but this is just an example] and burgers are $2. The result is that said person can still buy the same exact amount of burgers. The danger is when inflation overtakes salaries, or when inflation goes out of control in a very short amount of time. Argentina, for instance, has had a total inflation of 800% over the last 10 years. That's bad. In turn, cumulative inflation in the US has been of 21%- far more manageable. Central banks all over the world consider that an inflation rate of 2-3% yearly is actually good, as it encourages spending without making saving impossible and allows to reduce the value of the debt without wrecking the prize system in the economy, which is what happens when inflation goes bad: with 40% a year (Argentina- I have been there!), you literally cannot save and companies cannot give a value to their products or know how much money they need to put apart to restock their inventories, as they don't know how much things will cost in a few weeks' time when they sell out their current stock because the benchmark of value (the currency) has lost it all and fluctuates randomly every hour.
That is FAR from what's happening in the US. A yearly, predictable and constant inflation of 2-3 percent is manageable and won't disrupt anything, as companies can keep that estimation into account when providing for the future. Hyperinflation, though, only happens in countries whose entire economy is in shambles or after a war that has ruined half the country. As you can see, the US is suffering from neither and chances are it won't in the near future. People have been rumbling about "the collapse of the value of the dollar", but actually, last month, the value of the dollar increased by 0.2% nationally -
the US are in deflation!- and by far more in the international exchange rates (again, a year ago a dollar bought you 0.70€, now it buys 0.90€).
But scaremongers have been predicting hyperinflation every week since ever.
2010,
2011,
2012,
2014, etc. The truth is, a currency is worth what the goods produced in a country are worth and what the Government can do to manage the value of their currency. As long as oil is measured in dollars (even oil produced by Venezuela!), the US has an economy worth trillions, exports keep flowing and internal commerce goes up and the Federal Reserve is ready to do gambles like buying bonds, reducing interest rates and printing money when the banks don't have cash in hand, chances are people will keep wanting to own US dollars to buy the sort of things you need US dollars to buy (see: oil, but also technology and essentially anything made in the US anybody might want to buy). And if people want to buy things you need dollars to buy, the dollar will keep their value, simple enough.
I'd ask you to name some of the hyperinflation scaremongers so I can analyze their claims.