作者
莊希豐^* (淡江大學經濟學系)
陳亞為 (淡江大學經濟學系)

Authors
Shi-Feng Chuang^* (Department of Economics, Tamkang University)
Yah-Wei Chen (Department of Economics, Tamkang University)

中文摘要
本文引用 Hansen (1999) 門檻模型，針對 1960 年至 2005 年 62 個國家資料作橫斷面分析，客觀估計貿易自由化對高、低所得國家之所得分配影響。實證結果指出在低所得國家商品自由化大致會惡化國內所得分配，在高所得國家商品自由化大致上對國內所得分配無顯著影響；而外人直接投資對低所得國家所得分配無影響，在高所得國家外人直接投資將顯著惡化國內所得分配。此結果意味著各國可依其經濟發展程度適當地調整開放政策，以利國內長期經濟發展與所得分配。

Abstract
This paper empirically investigates the threshold effects of openness on income inequality. Specifically, we use Hansen's (1999) threshold regression model to examine whether the openness-inequality link varies with the degree of a country's income. By applying the model to 62 countries during the period 1996-2005, we find that there indeed exists an income threshold in the openness-inequality link. Moreover, the opening of goods markets increases income inequality in low-income countries. However, in high-income ones trade openness has minor effects. By contrast, foreign direct investment is found to increase income inequality in high-income countries and has an unimportant effect in low-income ones. These findings suggest that to reduce income inequality, the governments need to consider their positions in the economic development process and adopt relevant openness strategies.

中文關鍵字
貿易開放；外人直接投資；所得分配不均；門檻；HOSS 定理

Keywords
Trade Openness; Foreign Direct Investment; Income Inequality; Threshold; HOSS Theorem