Trade, Multinational Production, and the Gains from Openness
量化了开放带来的收益，不仅包括贸易，还包括跨国生产（MP），发现开放收益远大于贸易收益，且贸易与MP呈互补关系。
Much attention has been devoted to the quantification of the gains from trade. In this paper we pursue a broader and arguably more important exercise by quantifying the gains from openness. This notion includes not only trade but all the other ways through which countries interact. We focus our attention here on multinational production (MP), which in 2004 was more than twice as large as trade flows. We present and estimate a model where countries interact through trade as well as MP, and then quantify the overall gains from openness and the role of both of these channels in generating those gains. We build a model where trade and MP are alternative ways to serve a foreign market, which makes them substitutes, but MP also relies on imports of intermediate goods from the home country, which make them complements. The model also allows for “bridge ” MP, or export platforms, creating an additional channel for complementarities between trade and MP. Our results imply that the gains from openness are much larger than the gains from trade – this is thanks both to the large gains from MP and to our finding that trade and MP behave as complements.