Because US is fully federalized and is redistributing from the top down (californians and newyorkers pay for the midwest).

The big federally funded programs (military, social security, healthcare, infrastructure) take some pressure off the state's budget.

And because US citizens have less state identity than they identify with US the wealth transfers are easier to bear.

The us citizens that will say "I am American from Colorado(or any of the other 49)" are more common than EU people that will say "I am European from Germany (or any of the other 20+ Eu countries)"

The EU has union-level redistribution, especially for farmers, who, as in the US, are heavily subsidized.

US states sometimes get into the same kinds of problems. Look what's happening to Kansas right now, after a big tax cut. There's no escape for a state that screws up. They can't impose capital controls and keep people from moving their money out of state. They can't print money.

If the EU was a full financial union, individuals in Greece would have no problem withdrawing money from banks, because they'd be customers of banks in other countries. US states don't have their own financial systems. It's the combination of a common currency and separate banking systems that's the problem.

You can't really compare the redistribution in the States with the Euro area.

If some state like Kansas has problems, automatically, the federal budget cover the increment in social spending and that keep the aggregate demand in that state from going too low.

If some state like Greece has problems, automatically, Brussels make them to spend less in social programs in order to control its spending. The aggregate demand fall and the problems increase.

The Euro area is "designed" to be procyclical. And that is crazy.

Re: your first point, the same happens in Europe; the relatively rich west (like the aforementioned Netherlands) pays for the relatively poor newer eastern-european states, and the farming industry in countries like Spain, and with the recent problems in Greece, spends billions to try and get that country back on its feet.

" and the farming industry in countries like Spain,"

I don't know what this mean. The farmers in Spain are payed for not producing. I suppose the rational is protecting the farmers in France and the Netherlands. This is not redistribution in the sense of "rich" helping "poor".

The big difference is that a country in Europe has his own economy completely detached from the rest of the EU while in the US the federal state will provide money coverage for the basic state services and absorbs economic shocks distributing it on the whole country.

Couple of things

1. In the US, states aren't responsible for bailing out banks the Federal Reserve is. You don't see things like Ireland having to bail out a bunch of insolvent international banks.

2. In the US you see about 100-200 billion a year in transfer payments. I've come to believe that these are essentially compensation paid to states with weaker economies to compensate them for having to do business in dollars.

3. Social Security and unemployment insurance are Federal not, not state programs. And exception is state pensions, where there are indeed problems.

4. Most states are limited in the ways they can borrow money and don't run deficits that are large percentages of GDP.

5. Politically there is a difference. With Greece when I talk to Europeans there is this a reflexive desire to impose collective punishment on the Greeks. You just don't see that in the US. I think that frees US policy makers to take practical measures that aren't available to the Europeans. Consider Puerto Rica, about 40% of the population of Greece, half the total debt. Just said, they're broke. As an American... oh well sucks to be a creditor. But the Federal Reserve isn't going to cut off banking in Puerto Rico and force them to do a fire sale of civil assets like the EBC.

How many states do you have where SS pays out pensions to people over 56 while people in the other states work until 65 or 67 and are supposed to fund it?

SS in the us is funded via a Federal tax on wages. Rules are uniform over the entire country. Also Social Security Disability Insurance covers disabled people, and it too is a Federal not state program.

Unemployment insurance is a Federally mandated program that's administrated by the states. In 2009 California's unemployment fund was depleted and the Feds just loaned California money. Currently our fund is in the red by 8 billion. Does anyone care? No.

It's just at an earlier stage, the eurozone is still very young.

Monetary union has of course always implied ever closer union and the gradual dissolution of nation states - full political and fiscal Union. So the squabbling over who will fund Greece is rather silly in this context, if you want a single currency and market you must accept all the consequences which follow. That will take quite some time though, and as with the formation of the U.S. this is often a messy process.

As others have already said, the main difference is that the US has true political and social union to go with the financial union (if anyone is interested, this state of affairs came about during and in the aftermath of the American Civil War - indeed the war was only possible because until then the states really were independant entities capabable of defying the federal government - this is of course no longer the case).

To make it more concrete, when Louisiana has financial problems, the first remedy for Louisianans(???) is to move to another state. The next remedy is for the federal government to step in and inject funds into the economy, which is pretty much what they do, taking those funds from wealthy states such as New York and California. This works, because if the federal government hangs Louisiana out to dry, they will potentially lose seats, and potentially the presidency, come next election, so even though it annoys the rich states a little, the best political strategy is to provide as much financial support to Louisiana as possible without pissing off the rich states too much.

In Europe this is not the case. Indeed, this is precisely the problem that has been debated over recent weeks. The rich states (err, state, because Germany is about it at the moment, although I suppose you could count in the UK as well) refuses to pump more money into Greece's economy. They consider the situation to be Greece's problem, and they aren't going to do anything to help. Politically, there is no impact on German leaders to take this stance - or even worse, there is a political advantage to take this stance, as only Germans vote for German political leaders. Socially, with two very different cultures, and two different languages, there is not much by way of social cohesion. There are not huge numbers of mixed German / Greek families capable of looking across the border and seeing "us", not "them".

Imagine a European political structure that was truly integrated: There is a European president that commands the European military, and controls the European budget which comes directly from taxes that the European government levies on it's people, instead of the budget being made up from funds allocated to the European government by it's member state governments (which is the case today). In such a case, the European president would be much more willing to listen to Greece's case than the German Chancellor is today, and we wouldn't have this crisis.

That in a nutshell is the difference between the US and Europe. It has long been the UK's biggest criticism of the Euro, and is on record as being the reason they decided to not join the Eurozone (no financial union without political union).

Amongst other differences: there's far more internal migration within the USA than within the EU.

(My opinion here, I know not everybody is going to agree). Because it took way more than 5 years to unify the American Dollar if I remember whereas the EU wants to go too fast, the local currencies were dropped really quickly and it destabilized the public opinion and the local economy. In people's mind, the euro is associated with inflation and decrease of purchase power. The EU is also way more diverse than anything close to the United States, no one thinks himself as European, there is no European identity (yet).

One main problem also is that anything coming from the EU has a bad reputation, the EU is perceived to be very bureaucratic and top-down (they are perceived to be too far from the average guy and not listening). It's not only in the UK, no-one wants to do a actually do a survey because they fear the results.

As a share of GDP, USA as a federal entity have many (10+) multiples higher budget compared to the EU entities. All the pork and military and other federal spending in the states act as an equalizer.

It took you 100 years, 10 depressions and 1 civil war to figure out how that needed to work..

Well for one thing (beyond what others have listed), the Dollar is the global reserve currency, which means US inflation is partially exported to the rest of the world - domestically the US only absorbs part of the inflation of its own monetization programs. The Eurozone can't as effectively export the hit its citizens take to their standard of living from QE currency debasement.