If we all hold that self interest is paramount or half of us even hold it as an ideal in which we seek to acquire more and our greed keeps us from using the money we hold the entire economic system collapses
Free market is based on the principals of keeping the money flowing and changing hands, the selfish among as try to hoard it, and from the time we were kids we're told to save our money
its no wonder then the economy collapses when nobody spends their money.
Then again we always hear about how we're the ones living beyond our means and how we're under water leveraged to the hilt in upside down mortgages. This greed and selfishness tells us to acquire more and more things and to be materialistic. So what then is our problem? Are we spending or saving?
The real answer is more likely to be that we are not the problem. You may ask where did I say that we were? The fact is that its a hidden premise suppressed by our own mind for a myriad of reasons. In establishing that we are or are not spending our money and that is somehow a problem it becomes that we are the problem through transitive properties. Yet as I said it is more likely in fact that given a small handful of people control the economy given that they control more than 90% of the money we realize that they are the problem. Those few hundred perhaps a thousand at most that have failed their duty to us and our economy simply hoarding it all as they slowly choke the life out of us and we do nothing to fight back.
This seems like an inevitability within the philosophy without some level of regulation. Though to each their own I guess, perhaps one day we'll realize how little we need money in the future.