About the book by Piketty! This seems to cover the major points with out nearly as much math and none of the history.
. . . As a consequence, the optimal tax policy is also two-dimensional: it involves a progressive tax on labor income and a progressive tax on inherited wealth. . .
| r > g | where r is the Return on Capital and g is the Growth Rate |
| k = y | where k is Capital and y is the Output (Yield?) |
| s = g | s is Savings and g is the Growth Rate |