There is a reason tax hikes never bring in the predicted government revenues touted by their advocates. The politicians use static analysis, which assumes people will not change their behavior when their incentives change. A 10% hike in tax rates is supposed to generate a 10% increase in tax revenues.
In reality, people respond to incentives. The rich can work less, invest differently, hire a more creative accountant, move to a lower tax state (or nation), substitute leisure for work (e.g., europeans), etc.
Taking changes in behavior into account in predicting the impact of changes in tax rates is called dynamic analysis, and is infinitely more accurate historically than static analysis. Of course, tax-raising politicians do not want to use it. Nor does the Congressional Budget Office (CBO), which is famous for being wrong in their predictions.
