Undervalued exchange rates are only one of the policies that countries use to boost exports and restrain imports, so that they run trade surpluses, while their trading partners (including the US) run deficits. Policies aimed at ensuring export-led growth also include export subsidies and barriers to imports.
低估的汇率只是各国用以推动出口并限制进口的政策之一。实施这样的政策使得该国享有贸易顺差而其贸易伙伴们（包括美国）则出现逆差。确保出口主导型经济增长的政策还有出口补贴和进口壁垒等。