The United States uses the U$.$S$.$ Model Income Tax Convention as a starting point for treaty negotiations, and European countries and trading partners employ the Organisation for Economic Co$-$operation and Development $($OECD$)$ Model Tax Convention. The United Nations tax committee has also produced a UN Model Tax Convention.

Please respond to the following:

$$ Compare the U$.$S$.$ model, OECD model, and the UN model treaties.

$$ Which of these treaties does more to reduce barriers to international trade and investment by decreasing tax barriers to the flow of goods and services? Provide evidence for your argument.