I don't know what optimal is, but the evidence is that giving more to the wealthy doesn't help much. My family is decidedly upper-upper-middle class, and I won't pretend that cutting my taxes will stimulate the economy. Extra money is going into loan repayment or savings. If my taxes went away entirely, I'd spend more, but not enough to offset the loss of revenue to the government.
I fully agree that there must be private investments, and indeed there must be wealthy people. Whenever I hear someone say "No one needs more than X dollars", I immediately know that I'm talking to an extremely naive person. However, I do think that the pendulum has swung too far in favor of the wealthy, not just in terms of taxes.
Edit: Just to be clear, dumping money into the pockets of average Joes isn't necessarily going to do anything to stimulate the economy either. The tax rebates showed that.
I fully agree that there must be private investments, and indeed there must be wealthy people. Whenever I hear someone say "No one needs more than X dollars", I immediately know that I'm talking to an extremely naive person. However, I do think that the pendulum has swung too far in favor of the wealthy, not just in terms of taxes.
Edit: Just to be clear, dumping money into the pockets of average Joes isn't necessarily going to do anything to stimulate the economy either. The tax rebates showed that.