本文利用合成控制法（synthetic control method），對臺灣在1991年之後的經濟成長率序列進行反事實分析（counterfactual analysis），以研究若臺灣未曾脫離之前（1962-1991）的經濟狀態，在此期間可能會有的經濟成長率序列；並由實際成長率序列與反事實成長率序列之差異，推估臺灣在1991年之後因各種經濟條件的改變，對經濟成長率序列產生的影響。我們並以同樣的方法，對南韓的經濟成長率序列進行反事實分析，藉此比較兩國在1991年之後的經濟表現差異。反事實分析顯示，在1991年之後，兩國各自的總和效果多數時間皆明顯為負，且均有隨時間推移而擴大的趨勢；此外，臺韓的經濟成長差異不僅來自兩國在此期間的經濟條件差異，亦相當程度地反映出兩國即使維持在先前之經濟狀態下也可能有的差異。

In this paper, we apply the synthetic control method to implement a counterfactual analysis for Taiwan's economic growth in the post-1991 period. The analysis explores Taiwan's economic growth in a counterfactual scenario where this period was still under the economic conditions of 1962-1991. We use the difference between the actual growth sequence and its counterfactual counterpart to identify the total effects caused by the structural changes in Taiwan's economic conditions. We also apply the same method to exploring Korea's economic growth in the same period, and compare the economic performance of the two countries based on the counterfactual analyses. We find that the total effects are negative and deteriorated over time for both countries. Moreover, the difference between the two countries' economic performance is due to the difference between their economic conditions in and before the post-1991 period.