Source of graph: online version of the WSJ article quoted and cited below.
(p. A23) Kurt Hauser is a San Francisco investment economist who, 15 years ago, published fresh and eye-opening data about the federal tax system. His findings imply that there are draconian constraints on the ability of tax-rate increases to generate fresh revenues. I think his discovery deserves to be called Hauser’s Law, because it is as central to the economics of taxation as Boyle’s Law is to the physics of gases. Yet economists and policy makers are barely aware of it.
. . .
The data show that the tax yield has been independent of marginal tax rates over this period, but tax revenue is directly proportional to GDP. So if we want to increase tax revenue, we need to increase GDP.
. . .
What makes Hauser’s Law work? For supply-siders there is no mystery. As Mr. Hauser said: “Raising taxes encourages taxpayers to shift, hide and underreport income. . . . Higher taxes reduce the incentives to work, produce, invest and save, thereby dampening overall economic activity and job creation.”
For the full commentary, see:
DAVID RANSON. “You Can’t Soak the Rich.” The Wall Street Journal (Tues., May 20, 2008): A23.
(Note: ellipses added.)