In a certain sense that's the goal: > Our research on eighteen OECD countries shows that, between 1975 and 2008, there was indeed a strong correlation between

In a certain sense that's the goal: > Our research on eighteen OECD countries shows that, between 1975 and 2008, there was indeed a strong correlation between reductions in top tax rates and increases in top 1 percent pre-tax income shares... higher top tax rates may discourage work effort... the incentives for [executive] rent-seeking are much stronger when top tax rates are low > there has been no correlation between cuts in top tax rates and average annual real GDP-per-capita growth Piketty wants to reduce inequality without damaging the economy, not specifically boost tax revenue from the rich. His claim is that raising top tax rates does discourage people from obtaining extremely high pre-tax incomes, but doesn't shrink the economy. There are several possible reasons for that, but the basic question Piketty cares about is whether you would stop being productive. Someone who trades off salary for a shorter commute, or spends less time angling for a raise, or even hides their money from taxes more effectively, is not necessarily producing less value. If you lost your motivation to seek more than $500,000/year (remember, this is about the top bracket), but continued to do equally GDP-boosting work elsewhere, that counts as success for this system.