The Collaborative International Dictionary of English v.0.48:

Voodoo economics \Voo"doo economics\, n. (Politics)
   an economic hypothesis, proposed by President Ronald Regan,
   that large cuts in tax rates would so stimulate the economy
   that the tax revenue on the increases in business and
   personal income would offset the anticipated tax revenue
   losses, so that such tax cuts would not increasing the
   federal budget deficit. Its believers do not consider the
   actual massive deficit increases subsequent to the 1982-83
   tax cut as being caused by the tax cut itself, but by other
   governmental policies. This hypothesis was graphically
   illustrated by the Laffer curve.
   [PJC]