Theoretical analysis based on models of growth and trade with heterogeneous firms

(1)构建了异质性企业国际贸易与经济增长的新模型；(2)企业生产率的事前分配是内生的。这与现有的研究形成了对比，在这些研究中，事前分布是外生处理的。(3)贸易自由化扩大了出口产业，缩小了非出口产业。虽然这一结果在文献中有报道，但重要的是要建立同样的结果在质量阶梯模型中成立。(4)贸易自由化无疑促进了技术进步和消费增长。(5)如果市场规模足够大或代表性消费者的时间偏好率足够小，则由于贸易自由化而增加社会福利。(6)研发补贴并不一定会扩大出口产业。同样，产业政策也不一定能促进技术进步。(7)上述基本结果在不存在人口增长的“规模效应”的模型中成立。这个研究项目导致了其他领域的研究。

(1) A new model of international trade and economic growth with heterogeneous firms was built (2) An ex ante distribution of firm productivity is endogenized. This contrasts with the existing studies where the ex-ante distribution is treated exogenously. (3) Trade liberalization expands the exporting industries and shrinks the non-exporting industries. Although this result is reported in the literature, it is important to establish that the same result holds in a quality-ladder model. (4) Trade liberalization unambiguously promotes technical progress and consumption growth. (5) Social welfare increases due to trade liberalization if the size of the market is sufficiently large or the rate of time preference of the representative consumer is sufficiently small. (6) R&D subsidies do not necessarily expand the exporting industries. Similarly, the industrial policy does not necessarily promote technical progress. (7) The above basic results hold in the model without "scale effects" in the presence of population growth. (8) This research project led to other areas of research.