China's international trade development and opening-up policy design over the past four decades

China's opening-up in the past four decades has gone through three waves: the extensive margin of opening-up (1978-2001), the intensive margin of opening-up (2001-2017), and all-around opening-up (since 2017). This paper explores these three stages of the country's economic reform. China's gains from trade have been inspired by different economic factors. Before the turn of the century, the large trade volume was due to the realization of comparative advantage based on the country's factor endowment. However, after its accession to the World Trade Organization, China's gains from trade have been due, in large part, to the realization of economic scale effects associated with the larger market.