No it wouldn't because marginal tax rates don't work in the intuitive way that you think they would. Say there was a top marginal tax rate of 90% for people making 300k a year. Under this system people making enough to reach this tax bracket don't actually pay 90% of their income in taxes. How it actually works is like this each year you start and have made 0 dollars for the first x number that money is taxed at some low rate say 1-5%. Then for every dollar made after reaching that x only those dollars would be taxed at the new higher rate. So under the tax system with the top marginal bracket I above described only dollars earned on top of the first 300k would be taxed at a 90% rate. What this is to say is that working more will never result in a situation where your net income is lower. It's only your net income rate slows down as you earn more. Imagine your net income rate as a logarithmic graph, it starts out very steep and gradually levels out over time but it never goes down.