3. Factors that influence international trade In the 1950s, imports and exports of goods and services constituted roughly 4% to 5% of U. S. GDP. In recent years, exports have accounted for approximately 12% of GDP, while imports have more than tripled to over 15% of GDP. Which of the following help to explain the increase in international trade and finance since the 1950s? Check all that apply.

International trade agreements such as the North American Free Trade Agreement (NAFTA)

Higher tariffs

Services such as web conferencing and teleconferencing that facilitate international meetings

Better high-speed rail lines