Piketty's Capital Tax Applied to 10 Richest Americans

In "Capital in the Twenty-First Century", (reviewed extensively here), Thomas Piketty calculates that with a 3% capital tax on fortunes over $10M, the US national debt would be paid off in 5 years.

This year's Fortune 400 just came out. I wondered, how would the 10 richest Americans be affected? Here's the result:

Name	2014 $B	Gain $B	ROC	3% tax $B	Net Gain $B
Bill Gates	81	9	11.1%	2.43	6.57
Warren Buffet	67	8.5	12.7%	2.01	6.49
Larry Ellison	50	9	18.0%	1.5	7.5
Charles Koch	42	6	14.3%	1.26	4.74
David Koch	42	6	14.3%	1.26	4.74
Christy Walton	38	2.6	6.8%	1.14	1.46
Jim Walton	36	2.2	6.1%	1.08	1.12
Michael Bloomberg	35	4	11.4%	1.05	2.95
Alice Walton	34.9	1.4	4.0%	1.047	0.353
S. Robson Walton	34.8	1.5	4.3%	1.044	0.456

It looks like the Waltons have pretty crappy investment strategies. Their ROCs (Return On Capital) are only 6.8%, 6.1%, 4.3%, and 4.0%. For the other 6 richest, Piketty's assertion that the normal returns of the very rich are 10% or greater appears to hold up: the returns are all between 11.1% and 18.0%. These 6 all would see their capital increase by over ~$3B, even after paying the 3% capital tax. The richest man in the US, Bill Gates, would still have had a capital increase of $6.57B.

Five years of this and the national debt is gone - and the rich still still getting substantially richer! With the 1% tax on Wall Street transactions raising $1T per year, annual deficits are gone too, with money left over for education and infrastructure. Debt crisis over! Wow, it really doesn't seem that hard, does it?

The data comes from this Yahoo article.