the person who is legally responsible for paying the tax may not be the one who actually bears the burden of the tax...the incidence of a tax depends upon the law of supply and demand, not the laws of Congress.
...Many observers view capital income taxes as highly progressive...However, economic analysis suggests that capital income taxes are particularly likely to be shifted, especially in the long run...capital income taxes may be partly shifted to workers through a reduction in wages.
...Because the estate and gift taxes are taxes on capital, part of their long-run burden is likely to be shifted to workers through a reduction in wage rates [This part] is therefore likely borne by ordinary workers who never receive a bequest or taxable gift.
For Discussion. How does the issue of economic incidence of taxes affect calculations of the progressivity of the tax system?