Trickle Down Economics Is Still Voodoo

The centerpiece of Mitt Romney’s tax plan is an across-the-board 20 percent cut in marginal tax rates. ... His plan rests on the assertion that lower taxes for high-income taxpayers will increase economic activity and employment... This assertion ... is not supported by the evidence. 

Over all, our research shows that tax cuts for the bottom 95 percent are much more effective than tax cuts for the top 5 percent at increasing job creation in the subsequent two years. Other analysts reach similar conclusions.
 

Via the Economist's View blog and Tax Cuts for Job Creators, by Laura D’Andrea Tyson and Owen Zidar, Commentary, NY Times.