I (Heart) the Estate Tax

"Fortunate Sons: New Estimates of Intergenerational Mobility in the United States Using Social Security Earnings Data," Review of Economics and Statistics:

Previous studies, relying on short-term averages of fathers' earnings, have estimated the intergenerational elasticity (IGE) in earnings to be approximately 0.4. Due to persistent transitory fluctuations, these estimates have been biased down by approximately 30% or more. Using administrative data containing the earnings histories of parents and children, the IGE is estimated to be around 0.6. This suggests that the United States is substantially less mobile than previous research indicated. Estimates of intergenerational mobility are significantly lower for families with little or no wealth, offering empirical support for theoretical models that predict differences due to borrowing constraints.

(emphasis added)

If you have to ask how much you have to be worth to pay the estate tax, you will never pay the estate tax.