And of course, as usual, most economists are wrong.
Take the case of the average American wage slave, living from paycheck to paycheck.
Raise his taxes.
What happens?
He (or she) needs more money to pay his bills. He has to get a second job, perhaps even start a side business.
Thus, in many cases, raising taxes will increase GDP, perhaps even leading to substantial wealth creation.
The question is, how much do tax rates impact productivity. This article points to some data that suggest that as rates increase, productivity decreases or evasion increases.