台灣地區廢五金的處理始自民國三十四年，而以民國五十五年為轉折點，開始逕向國 外進口廢五金以從事再生事業，歷年來對美麗寶島造成頗大的傷害；更因發現燃燒廢 五金會產生世紀之毒－－戴奧辛，而令人談虎色變，且在廢五金專業區內常有廢棄物 起火燃燒事件發生，亦造成不少的糾紛，故在民國七十六年通過「廢五金進口管制改 進措施」，然其內容多著重於行政上和管制，遂本文試圖從另一途徑來探討政府防治 污染的措施，即政府可以成本效益的觀點來制訂經濟誘因政策。 本篇論文係本著經濟學與污染防治的基本概念及成本效益的途徑，以「廢五金進口管 制改進措施」之執行內容為分析重點，來探討政府部門之防治污染計畫實施經濟誘因 的可行性，以期以最有效的方法達到一個環境可以負荷的標準，而使我國環境品質如 同國民所得般急速上升。 政府部門可以使用的防治污染之經濟誘因工具主要有二：一為品質工具；另一為價格 工具。品質工具係指政府先訂定一個環境品質的標準，然後據此標準限定廣商之污染 水準，在本文中將探討出售污染權及補貼二種防治污染的品質工具；價格工具係指對 排放污染者予以徵收排放廢棄物費，或在法律上制訂其損害人民身體健康而應賠償的 規定，在本文中將探討徵收排放費和補償兩種價格工具，而品質工具與價格工具二者 其實有互通之處。 然上述方法在使用時亦會有若干限制，本文將一一加以說明。

我國法令原則上禁止庫藏股的交易，但實務上相當盛行母公司透過本身可完全控制的子公司來買回母公司股票，從經濟實質的觀點來看，此一交易屬於實質的庫藏股交易。本論文之目的在探討我國「子公司買回母公司股票」之實質庫藏股交易的資訊內涵，是否和資訊假說的含意相符；其次驗證對於發生諸如借殼上市之經營權移轉情形的公司而言，「子公司買回母公司股票」交易和公司大股東出脫持股俾追求自利的經濟誘因是否有關。研究主題一共發展3個研究假說，主要擬瞭解我國子公司買進母公司股票之交易行為的資訊內涵，俾了解此交易傳遞之資訊本質，並評估市場反應是否和此資訊有關。第二個研究主題共發展4個假說，係探討借殼上市公司內部人在借殼成功後，是否會利用子公司買進其借殼時增加的持股或融資交易的股票，俾舒解資金壓力。此外，亦驗證交易過程中的股價行為，是否和內部人為極大其獲利水準而可能進行股價操縱的股價行為相同。 　　本論文是以84年至87年為研究期間，兩個主題的樣本係相互獨立。實證結果顯示：關於主題一－子公司買進母公司股票傳遞之資訊本質，本研究發現，平均而言，以子公司買進母公司股票當季與後續四季為基準，母公司在此交易的後續期間並無表現出優於預期的盈餘績效（相對於配對公司），而且在交易後亦無法觀察到分析師對母公司盈餘預測有顯著的正向修正（相對於配對公司）。另外，在控制內部人淨買入、公司規模、子公司購買股數、資金需求與產業趨勢等變數後，本研究並未發現子公司買進母公司股票時的股價反應，和母公司當季與下一季的異常正向盈餘績效有顯著的正向關係。總而言之，國內實務界雖然宣稱子公司買進母公司股票係傳遞看好母公司未來前景的訊息，但本研究的證據顯示，這項交易並非傳遞母公司未來盈餘變動的資訊，同時，此交易引發的正向市場反應，似乎並非來自投資人對母公司未來績效的預期，故從股價操縱的角度來看，此一股價效應可能來自於母公司刻意創造，但其實與母公司經濟實質無關的泡沫股價。 　　關於主題二－借殼上市公司透過子公司買進母公司股票之經濟誘因－的實證結果顯示：在控制其他因素後，借殼上市公司在借殼成功的後續期間，子公司買回母公司股票之交易發生後，相較於無此交易的配對公司而言，其內部人持股比例和融資餘額有顯著降低的情形。基於這類公司大股東有套現的特殊動機，故可合理懷疑，這項證據和內部人籍子公司買進母公司股票來出脫持股俾套現獲利有關。此外，分析結果發現：子公司買回母公司股票交易前有正向的股價效應，此一股價行為和內部人操縱下的股價型態相符，但交易後的股價水準則並未顯著低於交易前的股價。吾人推測此一結果，可能肇因於投資人受到誤導，以致本研究未能觀察到後續反轉下跌的股價行為。 　　整體來看，子公司買進母公司股票之交易並非如實務界所宣稱，係傳遞公司未來前景較佳之資訊，反而可能和內線交易與股價操縱有關。因此，本研究支持目前財政部擬議中嚴格禁止或限制母子公司交叉持股的方案，此外，本研究應有助於投資人做投資決策時，對於母子公司交叉持股的本質有所了解。 / Companies are not allowed to buy back any of its own shares except in some special cases according to the Company Laws in Taiwan, but the practice that parent companies repurchase their own stocks through subsidiary companies (which is so called parent-subsidiary cross-holding transactions) is popular currently. From the economic substance view, the parent and subsidiary companies are treated as a single economic entity, and the parents' stocks held by their subsidiaries are treasury stocks in substance. Since the authorities and investors are all concerned with this issue, and previous work in this area is limited, this thesis investigates the information content and economic incentives of these transactions. Specifically, there are two research questions in this dissertation. The first is whether the transactions that subsidiary companies purchase parents' stocks convey any information about parents' future prospects? And whether the stock price reactions around announcement dates are positively related to parents' subsequent earnings changes. The next question is whether these transactions are motivated by insiders' intent to sell their own shares for self-interest? And is the stock price behavior around announcement dates consistent with the explanation that stock price is manipulated? 　　The findings of the first research question are as follows. First, I find no evidence that there are positive aggregate unexpected quarterly earnings relative to a size and industry-matched control sample over the announcement quarter and subsequent four ones. Second, the significant evidence that there are positive revisions of earnings forecasts by analysts around announcement dates also cannot be found. Finally, a regression analysis shows that there is no significant positive relation between positive abnormal stock returns at announcement and positive quarterly earnings changes over quarter 0 and quarter I. In summary, the results are not consistent with the implication of the information hypothesis. I find no systematic support for the firms' claims that the meanings behind parent-subsidiary cross holding transactions are to convey managements' private information about parents' favorable prospects. 　　With regard to the second research question, I focus primarily on those listed companies whose controls are obtained by unlisted companies through purchasing outstanding shares in the open market, these companies are not included in the sample of the first question. As predicted, I find systematic support for the hypotheses that shares owned by insiders and companies' margins decrease relative to control groups immediately following parent-subsidiary cross holding transactions announcements and that abnormal stock returns before and at announcements are positive. However, I show that the abnormal stock returns after the announcements do not fall bellow those before announcement dates significantly. In summary, the findings indicate that these transactions maybe a means for informed insiders to sell their own shares at manipulated high prices in order to alleviate the huge capital pressure by self-interest. 　　Overall, the transactions that subsidiary companies purchase parents' stocks are more likely to have relation to insider transactions and stock price manipulation, rather than convey favorable information about parents' prospects as what firms claim. Therefore, this thesis supports an act of prohibiting or limiting parent-subsidiary cross holdings proposed by the Ministry of Finance strictly. Besides, the results in this thesis may be helpful for investors to understand the nature of parent-subsidiary cross holdings when they make investment decisions.

本研究旨在探討中國大陸如何運用經濟工具與菲律賓、越南應處南海爭端。參照Keohane及Nye非對稱互賴理論（asymmetrical interdependence）提出之敏感性（sensitivity）、脆弱性（vulnerability）概念，本研究分析中國大陸自1997年採取「魅力攻勢（Charm Offensive）」策略，為其創造可供運用經濟誘因（economic attraction）及經濟脅迫（economic coercion）之戰略空間，期能使菲、越等經濟實力相對弱勢國家，在領土爭端方面知所退讓。然而，從經濟誘因之敏感性以觀，研究發現菲、越兩國例證，均無以支持經濟誘因能說服相對弱勢國家減緩聲索之論述。針此，研究者提出「信任（trust）」或可作為補強Keohane及Nye分析框架要項之一；意即中國大陸與其經濟夥伴之間若政治信任不足，則中國大陸欲藉提供經濟誘因，促其經濟夥伴在領土爭端有所退讓，勢必存在相當難度。另從經濟脅迫之脆弱性以觀，研究發現菲、越兩國例證顯示，有別於運用實質性手段（substantive measures）施壓造成之短期損失，採取象徵性手段（symbolic measures）所映射之高度風險與不確定性，對於威懾經濟實力相對弱勢國家，可能更具效力。 / This study explores how China has employed economic instruments in handling South China Sea disputes with the Philippines and Vietnam. Borrowing Keohane and Nye’s notations of sensitivity and vulnerability in asymmetrical interdependence, this study analyzes how China’s charm offensive strategy developed since 1997 has created tactical spaces for China to utilize economic attractions and economic coercions in making her weaker economic partners to concede in territorial disputes. In terms of sensitivity to economic attractions, nevertheless, findings in both cases fail to support the argument that economic incentives would persuade the weaker parties to refrain their claims. I argue that one of the missing elements in Keohane and Nye’s analytical framework is “trust”. Without sufficient political “trust” between China and her economic partners, economic attractions to induce concessions could hardly work. In terms of vulnerability to economic coercions, findings in both cases suggest that compared to the substantive measures stressing the short-term loss, the symbolic measures projecting to high degree of risks and uncertainties might be more effective to deter the weaker parties.