Yes, usually defined as an income range.
Perhaps we can agree that the "middle class" are those persons not of "lower class",
And not of "upper class".
"Middle Class" then can not include those (whatever their income) without income producing property since they then must be "lower class".
So your theory means a shoe repair shop owner who earns $25,000 a year is middle class while a wage earner who makes $1,000,000 a year is not middle class or upper class?
That's one way to show the middle class is shrinking. Change the definition to the point of uselessness. Why not use a silly, much easier definition, like range of income?
You never did answer my question...If we returned to a gold backed dollar, do you think we could find enough new gold each year to expand the money supply enough to prevent deflation?
From wikipedia, there's 155,000 tonnes mined ever and 2500 tonnes mined per year. But a more meaningful comparison might be the 8133 tonnes in official U.S. holdings and 252 tonnes mined in the U.S. each year which is 3% growth.