Today I'm presenting a paper at the meetings of the Canadian Economics Association: "Bargaining power and the incidence of taxes on high earners in Canada." The bottom line is that once you take into account the fact that high earners have bargaining power - that's why they are high earners in the first place! - then it's by no means clear that increasing the top marginal personal income tax rate will result in a progressive redistribution of after-tax income.
This is a theme I've been pursuing for years. From a post I wrote in November of 2009: