It has been noted that in the USA, that consumer spending is the main driver of GDP growth/retraction.

Given a reasonable current job (needs met, plus potential savings), is it more ethical to spend none, some, or all of the potential savings?

Any impact of my spending on the greater economy is going to be insignificant. Furthermore, anybody who expects me to spend when I have an economic incentive to save is a dingbat.

It can be argued that acting in the greater good is always a dingbat move.

I like barbecue. A lot. Especially piggy meat. Anyone who expects me to not eat piglet when I have enjoyment of piglet flesh is a dingbat.

I don't find a qualitative difference.

I think expecting someone to act for the greater good is dumb, yes. Expecting people to do so en masse is especially dumb.

This applies to both vegetarians who think people will just give up meat because "it's the right thing to do" and economists who think people will start spending for a similar reason. But the economists are much worse - for them to be so out of touch with human economic behavior, given their field of study, is inexcusable. (Then again, I think the efficient market hypothesis represents the same basic error, and it's real popular among economists - maybe we aren't working with the shiniest apples in the barrel from the start).

far more, maximising debt amust be a moral obligation.

Its a seriously messed up view of the world. GDP is not the holy grail.

I am pretty sure that not buying crap you don't need on credit with terrible terms is unamerican.

I don't see an ethical issue with an individual in a fairly wealthy society choosing to hoard money. If someone were hoarding a needed item with limited availability, that would be a different scenario.

I don't think morality should be an issue when it comes to savings in relation to the economy. The economy has existed for a long time on the principle that people do what's in their own best interest when it comes to spending/saving (Smith).

Spending driving growth is a myth.

Agreed.

The bolded part sounds like money.

Money (depending on what you mean) is neither needed nor in limited supply.

The engine of wealth is precipitous debt

Money = (for the purpose of argument) something that you can buy necessities and non-essentials with.

Fresh water is also not in particularly limited supply either. It is just concentrated in some areas more than others.

If you save your money at a bank, then fractional reserve banking may be a relevant concept. You are not necessarily lowering consumer spending by not saving yourself.

I think it's partially incorrect to say that consumer spending is the main driver of growth or retraction. This is largely true in the short run-consumer spending falls so businesses lay off workers further depressing consumer spending, etc. In the long run however growth is driven by growth in productivity (i.e. technology, production methods, etc.) and eventually those factors end up dominating. Savings rates tend to effect the level of performance but not the long run growth rate.

In any event, that doesn't mean that saving is bad. For one thing, saving simply substitutes spending now for spending later. Now, more spending now might lead to a more robust economy now which might lead to people being able to both consume and invest more in the long run, but it also increases the risk for the type of debt/leverage crisis we've encountered recently which can lead to a precipitous drop in economic performance later as people who have run up excessive debts are forced to curtail spending to pay them down.

The point being that the original premise is at best uncertain, and likely actually false. But even if it weren't false, it still doesn't follow that it's immoral to save. Many moralities would state that people need to first be responsible for those closest to them-if your family ends up starving in ten years because you didn't save any money today, then whatever nebulous possible gains in the overall economic performance your spending caused is probably not enough to offset what you've done to your family. In order to argue that savings is immoral, you have to take a very, very broad view of what moral obligations people have.

When the majority of money is created and sustained through lending (and most of the rest is brought into existence by fiat), I don't think it can be viewed purely as a medium of exchange any more. But obviously it's still used as such so it fits this definition. Still, I would call necessities "necessary," not any medium of exchange.

I don't think fresh water is limited in such a way or to such an extent that hoarding fresh water in case of disaster is immoral.

Furthermore, fresh water is limited by physical processes, nobody can just wave his hand and make fresh water appear out of nowhere. So, while comparisons can be drawn between the availability of fresh water and the availability of money, the two are fundamentally unlike.