If your taxes go up 5% tomorrow, would you work 5% less?
Even Slate, which is hardly a right-wing bastion, concedes that there is an effect (http://www.slate.com/articles/news_and_politics/explainer/20...)
If we subjected you to a 99% tax rate tomorrow, would you work less than before? A yes answer is all that is needed to concede the point theoretically. Then, we're just arguing about magnitude. And I just don't believe you if you answer no: Who is going to work a full-time $50,000 a year job when they're only taking home $500/year?
For further reading, Paul Graham has argued that redistribution through higher tax rates leas to less entrepreneurship (http://www.paulgraham.com/inequality.html)
If I'm making enough to pay for all of my needs and wants after the rate goes up, then I'll probably work less... Because what's the point?
If the difference is whether I can pay rent or not, then I'll probably work more.
The Slate article states that when income tax rate increases, the rich report less income, by fudging their taxes. It says nothing about rich people expending less effort.
I reread your comments (upthread). I imagined you were trotting out the "discouraged rich people" trope. My apologies.
It's rich people who have the most elastic working hours and income.