此博士論文乃是以兩國福利受兩國交易成本及關稅的影響、以及兩國 資本所得稅率在就籍與就源課稅兩種稅制下受交易成本及資源稟賦的 影響做為分析的主軸, 以探討交易成本不一致下的國際產業移動之驅 動因素, 以及由此而產生的各國之福利水準和各國各種政策在不同條 件下對於福利的影響, 包含以下3 篇論文。 論文1: 不對稱貿易成本下之雙邊關稅的福利分析 當貿易成本存在時, 關稅的上升或下降對於經濟體系的福利變化之分 析目前仍少有廣泛討論, 本文之目的即在於分析此情況下關稅之存在 是否為兩國之間的次佳選擇之議題。在此, 我們依Dornbusch et al. (1977) 所建立的兩國連續商品空間之貿易模式內生模型進行分析。本 文證明, 當雙方貿易存在出口貿易成本時, 若本國出口成本高於外國 時, 兩國同步提高關稅將會使兩國皆減少出口, 本國所節省的貿易成 本將轉換為本國自行生產所支付的工資。此時, 若兩國經濟規模相同, 則本國的相對工資將會上升; 若本國之人口規模大於外國, 則不但本 國福利上升, 加總後之世界總福利亦會上升。當貿易成本為零時, 本文 則與Dornbusch et al. (1977) 及傳統上文獻的分析之結論一致, 課徵 關稅將使福利下降。因此, 當兩國間存在不對稱貿易成本時, 即使市場 為完全競爭, 零關稅亦非兩國之間的最適貿易政策。 關鍵詞: 貿易成本, 福利, 人口規模, 次佳理論 JEL 分類代號: F15, F42 論文2: 不對稱境內物流成本下之租稅與公共投入競爭 對於不同資本課稅原則下資本稅率與廠商選址之均衡分析, 本文設立 不完全競爭之兩國一般均衡模型, 探討廠商的區位選擇以及兩國間的 租稅競爭在不同的資本所得稅制及各國不同的基礎建設水準下所受到 的影響。在此, 資本所得課稅分為就籍課稅及就源課稅兩種方式, 而各 國之基礎建設的影響則為當地廠商的對內交易成本及對外貿易成本。 本研究發現, 不論是採取就籍課稅或就源課稅, 若兩國的資源稟賦及 基礎建設完全一致時, 則一國須採取降到底部(race to the bottom) 的政策, 透過較低之資本稅率才能使得本國的廠商集中度大於資本豐 富度。當兩國之間的資源稟賦及基礎建設不一致時, 則豐富的資源稟 賦及良好的基礎建設可使一國即使設定較高的資本稅率依然可以擁有 較高的廠商集中度。另一方面, 若原本兩國之貿易成本相同, 若一國以 全球化作為政策方向, 以改善對外貿易基礎建設而使跨國貿易成本下 降時, 將使得境內物流基礎建設較佳的國家的廠商集中度提高, 即使 此一貿易成本下降乃是由對手國所達成亦會得到此一結果。因此, 一 國應優先致力於在地化改善其境內基礎建設再進行全球化之作為。另 一方面, 就福利效果而言, 本研究發現, 改善本國之基礎建設可提高本 國福利、損及外國福利, 將會存在以鄰為壑的效應。當兩國經濟規模一 致、交易成本一致時, 則不論何國改善基礎建設, 加總的世界總福利將 會上升。 關鍵詞: 全球化, 在地化, 基礎建設, 租稅競爭, 福利分析 JEL 分類代號: R12, R53, F21 論文3: 不對稱對外出口成本下之租稅與公共投入競爭 本文設立一個兩國之間存在不對稱的境內物流成本及對外貿易成本, 以分析政府部門的不同公共投入對於其資本稅率及國民福利的影響。 本研究發現, 當兩國之間的對外貿易成本決定於各自的基礎建設與物 流通路時, 改善本國之境內物流基礎建設及對外貿易基礎建設以降低 本國的交易成本將可明確的提高本國的廠商集中度, 使得本國得以擁 有較高的資本稅率臨界值。同時, 當本國之交易成本降低時, 外國會受 到此一政策的負向影響, 使得其廠商集中度降低, 資本稅率的臨界值 亦因而降低。因此, 本國不論是改善境內或對外的基礎建設以降低交 易成本, 皆是以鄰為壑的政策。若就福利效果而言, 改善本國的基礎建 設以降低本國的境內及對外之交易成本皆可使本國的福利上升。就世 界福利而言, 當兩國原本的經濟規模相等、相對交易成本相等時, 世界 之福利將會因而上升。 關鍵詞: 貿易成本, 基礎建設, 租稅競爭, 租稅原則, 福利分析 JEL 分類代號: R12, R53, F21 / This main issues of this dissertation are the effect of asymmetric trade costs and bilateral tariffs on the welfare of the two countries, and the effect of capital tax competition on firms’ location choice under asymmetric trade costs and capital endowment of the two countries. Under these model setting, I discuss the welfare effect of trade policy and public infrastructure by the following 3 essays. Essay 1:The welfare Analysis of Bilateral Tariff under The Asymmetric Trade Costs. Although a large number of studies have been made on the welfare effect of bilateral tariff, little is known about what will be different if the trade costs are embedded in the international trade. The purpose of this essays is to analyze whether the bilateral tariff will be the second best choice under this kind of circumstance. In this essay, it is shown that the wage of the home country will increase from the saving of its higher trade cost if the two countries impose the bilateral tariff and it contribute to less trade between the two countries. If the home country own more population then the foreign country, then the world welfare will increase by the much more increase of the home country welfare. It is also shown that the welfare will decrease if there is no trade cost between the two countries, and this conclusion is in line with Dornbusch et al. (1977). Hence, the existence of asymmetric trade cost will change the traditional conclusion that bilateral tariff will be harmful to the two countries if the market is perfect competition. Keywords : trade cost, welfare, population size, second-best theroy JEL classification : F15, F42 Essay 2: The Tax and Infrastructure Competition under the Asymmetric Homeland Transport Costs This essay build a two-country general equilibrium model with monopolistic competition to discuss the issue of capital tax and the firm’s relocation under different taxation principle and different international trade cost and domestic transport cost between the two countries. In this essay, there are two kinds of taxation principles : the source-based principle and the residence-based principle. The globalization policy is to lower international trade cost, while the localization policy is to lower the domestic transport cost. The first conclusion from this essay is that : no matter what kind of taxation principle, there will be “race to the bottom” tax policy between the two countries for the purpose of attracting more firms if their endowments and infrastructure are the same. When their endowments and infrastructure are asymmetric, the country with better infrastructure and much more endowment can impose a higher capital tax and still own more firms then the other country. The second conclusion from this essay is that the country with better domestic infrastructure will benefit from globalization policy, even it is the unilateral policy of the other country. Hence, localization policy has higher priority than the globalization policy. Besides, this essay also shows that the localization policy will enhance the domestic welfare and lower the foreign welfare. Hence, localization policy will have the effect of beggar-thy-neighbor. However, the world welfare still increases from this policy. Keywords : globalization, localization, infrastructure, tax competition, welfare analysis JEL classification : R12, R53, F21 Essay 3:The Tax and Infrastructure Competition of The Two Countries with Asymmetric Export Costs This essay builds a two-country location model with asymmetric domestic transport cost and international trade cost to analyze the effect of infrastructure on the tax rate and welfare of the two countries. There are perfect capital mobility between the two countries and the transport cost and trade cost is decided by the location of the firms. Hence, its cost will be the result of the infrastructure policy of each country. It can be derived from this essay that the improvement of domestic or international infrastructure of own’s country can increase the concentration of firm and lead it to be capable of imposing a higher capital tax. Hence, the improvement of domestic and international infrastructure in one country will be “beggar-thy-neighbor” to the other country. For the welfare effect, it can also enhance its own welfare. When the two countries are of the same economic size and face the same relative trade and transport cost, the world welfare will increase from the improvement of infrastructure of either country. Keywords : trade cost, infrastructure, tax competition, tax principle, welfare analysis JEL classification : R12, R53, F21