QUALITY LADDERS IN A RICARDIAN MODEL OF TRADE WITH NONHOMOTHETIC PREFERENCES
研究了即使各国初始生产力相同且变化一致，非齐次偏好与质量阶梯共同作用下，贸易仍可能因比较优势导致专业化模式不同，从而引发收入差距扩大。
The North–South trade literature has traditionally explored conditions under which international trade might further magnify income disparities between the advanced North and the backward South. We show that even when no single country is initially more advanced than any other one and productivity changes are uniform and identical in all countries, trade may still be a source of income divergence when nonhomothetic preferences and quality ladders are jointly taken into account. Income divergence will be experienced when comparative advantages induce patterns of specialization that, although initially optimal for all countries, do not offer the same scope for quality upgrading of final products.