The wealthy would respond to such a system by giving all their stuff to their kids before they die. It always amuses me when people prescribe magical tax plans in a static world as if people won't change their behavior. Despite thousands of changes in tax law over decades, the maximum level of revenue the government has been able to extract from the population has remained remarkably constant[1]
[1]http://www.heritage.org/federalbudget/current-tax-receipts