利益團體、民營化與關稅政策

INTEREST GROUPS, PRIVATIZATION AND TARIFF POLICY

本文考量經濟體系存在的政治失靈現象，將利益團體對政府提供政治獻金並進行遊說的行為，導入政府決定民營化與關稅政策架構中，檢視在此設定下的最適釋股比例與關稅政策，以及對社會福利水準的影響。文中發現：存在利益團體的遊說行為時，會使得政府制訂較高的釋股比例、較低的關稅稅率（甚或補貼）政策；其次，相較於不存在利益團體遊說行為而言，存在利益團體對本國政府提供政治獻金進行遊說行為，反而會讓本國社會福利水準提高，並對兩國社會福利水準有著柏拉圖改善（Pareto improvement）效果；其三，本文延伸探討兩國簽訂與未簽訂自由貿易協定的情況，指出兩國總和福利水準的高低，取決於利益團體的遊說效率；最後，就Wang and Chiou （2015）所認為民營化與關稅政策的等價性性質，在本文的分析架構下，則有著相異的論點。

This paper incorporates the political contribution and lobbying activities of interest groups into governments’ decisions on privatization and tariff polices. Under this condition of government failure, we re-examine the optimal privatization and tariff policy, as well as their impact on social welfare. First, it is found that the optimal level of privatization will be higher and tariff will be lower (or even subsidy in some cases) whenever lobbying exists. Second, the domestic welfare will be higher under political contribution than that without, and produces Pareto improvement for both countries. Moreover, to extend the situation of trading countries with or without a Free Trade Agreement, we find that the changing direction of aggregate welfare depends on the efficiency of lobbying. Finally, the equivalence between privatization and tariff policies of Wang and Chiou (2015) will not hold under our framework.