The biggest source of disagreement tends to involve whether or not changes in marginal tax rates in selective areas influence economic growth over time. Supply side economists suggest that they have the data to prove that they do, and others may argue with their conclusions.

It can be argued that all other things being equal, capital investments will flow towards the most favorable tax rates because this will yield the highest after tax returns, which by the way also happens to be very good for economic growth and tax revenues. Also, the more income after taxes citizens have, the more money they will have available for debt reduction, spending, saving or investment, all of which tend to be positives for the economy.

Higher economic growth tends to be associated with higher employment, and potentially more rewarding work if more value added businesses are allowed to start up and grow. The welfare of everyone is better served by a more prosperous society than a slow growth economy stripped of value creating industries. Prosperity has the potential to be a win-win for everyone. Governments, which continually spend beyond their means eventually, fail, as do the citizens that they serve.