Any tax action that Congress takes requires a revenue estimate — except for treaties. That’s a budget rule, adopted by Congress. The revenue cost of treaties is isn’t being analyzed — but there is a cost, because treaties only cut taxes. Treaties can’t raise taxes, because revenue raisers must begin in the House of Representatives — and only the Senate gets in on treaties. Occasionally, the beneficiaries of tax treaties are wealthy individuals, but usually they are multinational corporations — entitled to free speech under Citizens United. Here’s an explanation and more, from my former colleague Pat Driessen from Joint Tax: Tax Notes, Vol. 135, No. 6, 2012, http://papers.ssrn.com/sol3/papers.cfm?abstract_id=2069356.