Downward Mobility: "The Millionaire Decay Function"

Continuing our traipse through feeds we read but don;t link to often enough.
From Political Calculations:

Did you know that the most downwardly mobile members of society are millionaires?
It's true, and what's more, we have the data and math to prove it!

Our featured chart today was originally produced by Veronique de Rugy of the Mercatus Institute, which is based upon data from the IRS and analysis by the non-profit Tax Foundation.

Here, the story begins in 1998, when the IRS reports that there were approximately 675,000 tax returns with adjusted gross incomes of $1 million, or more.

[Side note: The traditional definition of a millionaire was someone who had accumulated at least one million dollars in total assets. However, since the word was first documented back in 1826, the effect of inflation is such that perhaps a more modern definition would be those who earn incomes of at least one million dollars in a year. In any case, $45,000 in 1826 dollars is roughly the equivalent of $1 million in 2012, going just by changes in the Consumer Price Index.]

Then, beginning in 1999, following the tax returns filed by the same people, the number of those with incomes over $1 million begins to drop dramatically - by nearly 50% in the first year!...MORE 

The whole blog is worth a look.
He has a nice calculator that links to Professor Schiller's Cowles/S&P 500 1871-2011 database:
The S&P 500 at Your Fingertips

As I've said:

We're kind of fond of old Doc Shiller.
In addition to publishing "Irrational Exuberance" in March, 2000 with the NASDAQ hitting its all time closing high of 5048 (subsequent low 1114, how's a 78% decline grab ya?) he is the keeper of the Cowles Commission records. From one of our Forecasting Equity Returns posts:

A subject near and dear to my heart. I may be the only person I've ever met who read every page of "The Cowles Commission's Common Stock Indexes 1871-1937".
[you must be a blast at parties -ed]

Here's his Yale homepage.
And  Irrational Exuberance.
Here's Common Stock Indexes...

....My favorite tidbit is the listing, among the pre-1871 industrials, of New York Guano.
Some things never change.
Here’s Yale’s (and my) gift:
http://cowles.econ.yale.edu/P/cm/m03/index.htm
It links to a big ‘ol hog of a PDF.

Here's "New York Guano".