+ I'm trying to find the citation but I think the average value in the US for households in the lowest wealth quintile is > 25% of their assets.
The people who run these systems have free reign to squeeze the poor because the poor have virtually no political power. (When was the last time you saw a politician throw a 50c/plate dinner?)
Assigning any part of poverty to poor people's inability to assess gold seems bafflingly detached from reality.
A $500 ring that is repeatedly used to secure pawn loans to cover short-term cashflow deficits is a lot like a savings account which seizes 80% of value on deposit and charges a $15~25 convenience fee on withdraws.
bafflingly detached from reality
You'll find alternative financial services, including voluminous material on jewelry as a store of value and collateral for pawn loans, well-represented in the academic literature. Would you like citations?
You also are committing a fallacy of "if X is true, then I must hold an immoral position Y, so X cannot be true". But logically either Y does not follow from X, or Y is not really immoral. (X = "poor people make bad decisions", Y = "the poor deserve their poverty") This logical fallacy has got you rationalizing everything that poor people do.
A fourth possibility is that patio11 and idlewords have priors which are not absolutely continuous w.r.t. each other. I.e., idlewords' prior for patio11's hypothesis is 0, and no amount of evidence will change his mind even if he is a completely rational. (It is by this mechanism that a rational Bayesian can also be religious. )
There are also utility deposits, auto insurance, etc. But, there are a tremendous amount of free resources available to poor people, from food stamps and food kitchens to clothing. It could be easier for someone with nothing to scrape together a few thousand bucks than someone in the middle class. If your food is subsidized, your income tax rate is low, and your lifestyle costs are low, e.g. not having to insure a home or expensive car, then you should be able to save quickly.
So, I'd assert that: Impulsive people, those severely uneducated in their economic alternatives, or those with little marketable skills stay poor because they continue to make bad decisions.
Both of these assumptions are likely untrue. Poverty makes the cost of many things higher. Banking is non-trivially more expensive. Public transport often ends up more than the cost of a car, and that's assuming you can afford a season ticket. Those in poverty often cannot. Rental is over a lifetime normally more expensive than buying - and if you're in poverty, you can often expect rental to include large deposits which you often won't get back.
For the impulsive thing, see http://yalepress.yale.edu/yupbooks/book.asp?isbn=97803001209.... Essentially if you're poor, there's a good chance that your marginal utility curve is upward, rather than downward sloping. Which rewards impulsive behavior in a way that is not the case for those who meet the normal standard of living in their society.
Precious metals are like an insurance policy in that you hope they never pay off.
There are many reasons why one might not want to hold cash or traditional investments. Especially if you are subject to wage garnishments, judgments, etc. As someone who has been pretty much as poor as you can be, I can say with confidence that those in the lowest wealth quintile don't have what most would consider to be a "portfolio", they are just getting by... its not a good plan to have a bunch of gold to pawn, but at least it is something that is highly liquid if necessary, as long as you can do math yourself to avoid being scammed.
Also, all investments go in cycles... if you bought and held gold instead of tech stocks in 1999-2000 you're killing it right now... if you bought gold in 2011 not so much. Poor people aren't poor because of their investment choices - they're poor because they live beyond their means and don't save.