中文摘要：

运用2000-2006年中国工业数据库和海关数据库的匹配面板数据,本文研究了进口竞争与多产品企业出口二元边际的关系。研究发现：（1）进口竞争显著提高了多产品企业出口的集约边际和扩展边际,且对集约边际的促进作用更强;（2）区分贸易类型的研究发现,相比于一般贸易,进口竞争对加工贸易的边际促进效应更加显著;（3）分行业回归的结果表明,具有比较优势的行业,进口竞争对出口边际的促进效应更为显著。使用系统GMM模型控制可能存在的内生性,发现进口竞争对集约边际和扩展边际的促进作用依然稳健。

英文摘要：

Using the matching panel data of Chinese industrial database and custom database in the period of 2000 to 2006, this paper studies the relationship between import competition and dual exporting margins of multi-product firm. This study finds that：（1）import competition improves the intensive and extensive margins significantly, and even stronger to the intensive margin;（2）with discretion of trade type, import competition improves the margins of processing trade more significantly than ordinary trade;（3）regression result of different industries indicates that import competition has a more significant improving effect in industries with comparative advantage. Controlling the potential endogeneity with system GMM method, the improvement of import competition on intensive and extensive margins is still robust.