In a New Republic blog, Alan Auerbach and Larry Kotlikoff discuss lifetime spending inequality. Due to taxes and income variability over the life cycle, this is much smaller than wealth or income inequality.
Auerbach and Kotlikoff write:
The top 1 percent of 40-49 year-olds face a net tax, on average, of 45 percent. … For the bottom 20 percent, the average net tax rate is negative 34.2 percent. …
Our standard means of judging whether a household is rich or poor is based on current income. But this classification can produce huge mistakes. … For example, only 68.2 percent of 40-49 year-olds who are actually in the third resource quintile using our data would be so classified based on current income.