On Thu, 05 Sep 2013 22:08:14 -0700, George Plimpton
wrote:

snip
Additional information on why income mal-distribution /
over-concentration and the resulting contraction of the
middle class

Once again, you're asserting something - two things, actually - that,
instead, requires proof.
snip

There will never be "proof" in the scientific sense, because
of the impossibility of replication / verification and lack
of control groups. The best that can ever be done is
accurate and honest record keeping, if possible objective
and numeric to allow cliometric/econometric analysis to
discover correlations or the lack thereof. This is what are
called quasi-experiments. One example of this in another
field is astronomy.
http://en.wikipedia.org/wiki/Cliometrics
http://en.wikipedia.org/wiki/Econometrics
http://en.wikipedia.org/wiki/Quasi-experiment

For example, by itself the following graph "proves" nothing,
but as this pattern is repeated across time and other
economies, the inference that when the top 1% own/control
over c. 23.5% of the national wealth, it results in economic
instability, and when no more than about 10-12% of the
national wealth is owned / controlled by the 1%, the economy
is stable and expansionary, keeps growing stronger.
http://en.wikipedia.org/wiki/File:20...percentUSA.png
for the entire article see
http://en.wikipedia.org/wiki/Income_..._United_States

A complicating factor in current analysis is the
proliferation of supranational corporations and tax havens
such that the determination of both ownership/control and
"national wealth" is increasingly difficult.

You are of course free to draw your own conclusions and
form your own opinions, but as Senator Moynihan so cogently
observed "Everyone is entitled to his own opinion, but not
to his own facts." – quoted in Robert Sobel's review of
Past Imperfect: History According to the Movies, edited by
Mark C. Carnes
http://en.wikipedia.org/wiki/Daniel_Patrick_Moynihan