http://www.federalreserve.gov/pubs/oss/oss2/papers/concentra...
Of course, wealth is not the only statistic we should study, as many households with little wealth may still have decent income. There are many factors to consider, but the simple fact is that a single family owns more than a third of Americans - a powerfully descriptive statistic of wealth inequality.
Let's assume the Walmart heirs acquired that money in absolutely the worst possible way: They went out and flat stole it from these 33 million households. If you took it from the Waltons and gave it all back, each of those households would receive a whopping $3,000 on average. Now, that's not nothing, but as a one time "refund" of wealth generated over decades it's not particularly impressive. If your household of four is at the poverty line, it would up your income by about 15% for one year.
And of course they didn't steal it. And I suspect that over only a decade (Walmart has been in business generating that wealth for five), the average low net worth household probably saved much, much more than $3,000 by shopping at Walmart. That's a win-win, and it's how an economy grows.
Dunno, it doesn't seem to be win-winning. Maybe because the pressures exerted by Walmart to get those low-low prices has forced the formerly decently paying manufactoring jobs overseas. So the guy who used to work at a factory now works at McDonalds making 33% of what he made without any decent benefits.
Nobody's entitled to a job, but when Walmart trims inefficiencies, it ensures that consumer spending is going towards the products of more efficient producers at their own stores and elsewhere, adding jobs where they can be the most productive.