貿易自由化與所得不均度間之非單調關係

THE NON-MONOTONIC RELATIONSHIP BETWEEN TRADE LIBERALIZATION AND INCOME INEQUALITY

二十世紀末，不少實證研究發現世界各國所得不均度上升的模式異於Heckscher-Ohlin模型之預測，因而認為貿易並非主因。然而最近不少研究，特別是基於異質生產者的模型，重新發現兩者間的關係具有理論基礎，並在實證上得到佐證。本文結合借貸市場的摩擦、個體資本稟賦的差異及需求彈性的內生性，內生地創造出所得不均度與貿易自由化的非單調（non-monotonic）關係。同樣立基於異質生產者的架構，雖然部分模型預測之關係為單調，然仍有部分模型呈現非單調的特徵，即使產生的機制與本文不同。

At the end of the twentieth century, many economists believe that trade is not the main reason causing income inequality within countries, because several empirical studies have found that the pattern of the rise in inequality does not coincide with the prediction of the Heckscher-Ohlin model. However, many recent studies, especially those based on firm heterogeneity, rediscover the theoretical basis and empirical evidence to support the relationship between the two. Based on the friction in the borrowing market, the difference between the capital endowment and the endogeneity of the demand elasticity, this paper generates the non-monotonic relationship between the inequality and trade liberalization. Based on firm heterogeneity, some studies predict the existence of a monotonic relationship, but others show a non-monotonic feature, although the mechanism is different from this paper.