A convertible bond (CB) is a hybrid security possessing the characteristics of both debt and equity. It gives the holder the right to convert the bond into a pre-specified number of shares (usually by the same issuer of the CB) until maturity of the bond, and may also contain additional features such as callability and putability. CB’s along with all hybrid securities are difficult to value due to their uncertain income stream. In this dissertation several convertible bond valuation models are suggested, but with particular attention to the calibration of the underlying inputs into the model and also by taking default risk into account, which is extremely important given the subordination of convertibles. The models range from the basic component models that decompose the CB into a straight bond and an exchange/call option; to more sophisticated ones consisting of stochastic interest rates, default risk, volatility structures, and even some exotics such as exchangeable and inflation-linked convertibles. An important aspect often missed by CB valuation models is the presence of negative convexity for extremely low share prices. As such a credit spread function dependent upon the underlying share price is introduced into the Tsiveriotis and Fernandes, and Hung and Wang models which improve upon the accuracy of the original models. Once a reliable model has been developed it becomes necessary to take advantage of convertible arbitrage trading strategies if they exist. The typical delta hedge, gamma hedge and option strategies that many convertible hedge funds employ are explained including the underlying risks with respect to the “Greeks”. Copyright / Dissertation (MSc)--University of Pretoria, 2009. / Mathematics and Applied Mathematics / unrestricted

For the past half a century, there has been progressive development in corporate finance theories, and among these, corporate financial decisions have been attracting the attention of outsiders. As the outsiders¡¦ learning process of the firm¡¦s private information determines the firm¡¦s value, managers who are concerned with outsiders¡¦ perceptions of their firms try to enhance their firms¡¦ short-term reputation through their financial decisions. However, up to this date, few reputation models have been applied to predict these financial decisions. Three corporate finance issues are involved to identify the reputation effects on corporate finance: (1) convertible bond call policies, (2) IPO decisions and activities, and (3) corporate financing policies. As for the first issue, this study constructs a two-period reputation model of a convertible bond call policy. This model concludes that in equilibrium, a firm with bad management quality and a bad reputation chooses to call, while a firm with good management quality or of a good reputation builds up it reputation by not calling the convertible bonds. This is consistent with the signaling theory proposed by Harris and Raviv (1985). However, the reputation model here identifies the call policy as a reputation-building mechanism rather than being only a signaling role, and suggests that the reputation rents resolve the discrepancies of the stock¡¦s post-call price performance. As for the IPO decisions and activities, this study performs another reputation model to analyze a firm¡¦s reputation effects on IPO activities, especially on the decision to go public. The results yield that a firm¡¦s reputation does affect its decision to go public. By listing equities publicly, firms with good management quality and a solid past would anticipate enhancing their reputations, and those with a poor past would anticipate building up good names. Furthermore, good reputation firms with bad management quality would anticipate maintaining their reputations by going public. On the other hand, it is found that good firms over-invest in building up their reputations and bad firms take advantage of their reputations to go public. Both result in firms¡¦ over-going public and IPO mispricing. This constitutes an alternative interpretation on IPOs¡¦ long-run underperformance and the sharp decline of the survival rate. As for the corporate financing policies, the other reputation model is constructed by taking both determinants, the costs of financial distress as well as the firm¡¦s reputation into consideration. The results show that good management quality firms with good reputations enjoy their financial flexibility between debt and equity. Bad management quality firms take advantage of their good names to issue equities, which leads to over investment. Good management firms lose their financial accesses due to bad reputations, which lead to under investment. Reputations would screen the bad management quality firms with bad reputations off the market. This dissertation concludes that reputations indeed affect the three selected corporate financial decisions and suggests further plow on more corporate finance issues.

近年來國內資本市場，因股票市場的熱絡交易而帶動公司及個人的理財風氣，投資標的種類不多及籌碼太少，一直是資本及股票市場正常發展的障礙之一，而證券主管機關亦深知，欲減少國內金融市場的投機色彩及暴漲暴跌的特性，唯有從增加供給面著手。因此，自民國七十八年起，主管機關即積極推介新的金融商品，首先推出的就是可轉換公司債(Conver-tible bond)，國內首宗正式發行可轉換公司債的公司是遠東紡織，之後有很多上市公司跟進，而推出後上市公司及投資人的反應均不錯，所以擬推出認股權證(Warrants)此一新產品。所謂認股權證是一種有價證券，其持有者有權在預定行使期間內，按認股契約所規定行使價格，向認股權證發行公司認購一定數量股票；而可轉換公司債是指在約定之一定期間內，以約定轉換條件，得轉換為可轉換公司債發行公司之普通股股票的一種公司債。認股權證如果與公司債搭配發行，與可轉換公司債同樣都賦予債權人轉變為股東之選擇權，兼具有公司債及股票性質。在國外的金融市場，可轉換公司債與認股權證是頗為流行且發展已臻成熟的產品，能提供更多公司籌措資金的管道及投資者的機會，但國內至今尚未推出認股權證，所以在我國發行可轉換公司債的熱潮正方興未艾之時，盼能參照國內外可轉換公司債及國外認股權證的法令規定，使國內認股權證能早日實施，況且此兩種新金融商品之投資性質很類似，相信此兩種商品在國內推出，對國內金融市場的發展有其正面的貢獻，因而引發本研究的動機。我國學術界近年來，亦有不少人士投入在認股權證及可轉換公司債的相關題材上進行研究，但這些研究多偏重在敘述與整理方面，而在評價模式及相關法律問題方面較為缺乏，因此本研究將著重此兩種產品在理論訂價模型與實務法律問題方面做深入探討。本人採用 Black & Scholes選擇權評價模式為基礎，再就其稀釋效果加以調整，則 Black & Scholes模型便可用來評價認股權證與可轉換公司債。國內發行可轉換公司債的相關法令規章則見諸於公司法、證券交易法、上市發行公司申請募集與發行轉換公司債處理準則內，本研究將詳細分析之。至於發行認股權證之相關法律問題是我們探討的重點，目前雖然證交法有認股權證的修正草案，但對於發行公司、投資人的權益尚未臻全，因而為了順利推動此類商品，宜更深入訂定管理辦法，並與可轉換公司債的法令關係比較，使兩種產品的市場受到保護並能欣欣向榮。

近年來，一方面由於台灣資本市場的發展日益蓬勃，另一方面則因台灣企業日趨大型化、國際化，相對於過去大都趨於現金增資、盈餘及資本公積轉增資等權益型態融資，現階段則更傾向多種融資管道及融資工具的交互運用，可轉換公司債市場發行者日益增加。 因此，本研究欲探討當公司選擇於國內融資，選擇現金增資與發行可轉換公司債之企業，兩者的財務特性是否具有差異；探討當公司選擇發行可轉換公司債，則發行國內可轉換公司債與發行海外可轉換公司債之企業，兩者的財務特性是否具有差異；探討台灣資訊電子業其從事籌資活動時之融資偏好概況。 本研究分別以Multinomial Logit模型以及Nested Logit模型分析民國89至93年間上市上櫃發行國內可轉換公司債、海外可轉換公司債或現金增資之資訊電子業公司，探究發行公司是否具備某種財務特性，而影響其融資選擇。研究結果發現： 1. 以Multinomial Logit模型分析時，選擇發行現金增資及國內可轉換公司債的融資選擇上，資產總額取對數值(表公司規模)、銷貨成長率(表成長性)愈小者，資產報酬率(表獲利能力)、負債比率(表財務風險)、營業利潤率標準差(表營運風險)、自由現金流量比率(表代理問題)愈高者，愈傾向發行國內可轉換公司債。選擇發行海外可轉換公司債及國內可轉換公司債的融資選擇上，資產總額取對數值(表公司規模)、銷貨成長率(表成長性)、營業利潤率標準差(表營運風險)、自由現金流量比率(表代理問題)愈小者，負債比率(表財務風險)、資產報酬率(表獲利能力)愈高者，愈傾向發行國內可轉換公司債。 2. 以Nested Logit模型分析時，選擇發行現金增資及國內可轉換公司債的融資選擇上，資產總額取對數值(表公司規模)及負債比率(表財務風險)愈高者，銷貨成長率(表成長性)、資產報酬率(表獲利能力)、營業利潤率標準差(表營運風險)、自由現金流量比率(表代理問題)愈低者，愈傾向發行國內可轉換公司債。選擇發行海外可轉換公司債及國內可轉換公司債的融資選擇上，資產總額取對數值(表公司規模)、銷貨成長率(表成長性)、營業利潤率標準差(表營運風險)、資產報酬率(表獲利能力)愈小者，負債比率(表財務風險)、自由現金流量比率(表代理問題)愈高者，愈傾向發行國內可轉換公司債。 3. 經由Hausman Test檢定其融資選擇之間的IIA條件之後，發現此三項融資選擇之間無任何相關性，因此可知其適用之模型為Multinomial Logit Model。 4. 對於台灣的資訊電子產業而言，就其財務特性中之公司規模、成長性、獲利能力、財務風險、營運風險以及自由現金流量比率看來，發行海外可轉換公司債均應至少屬其融資時的前二位選擇。 5. 影響企業傾向選擇發行海外可轉債的機率程度由大致小排列為：公司規模、獲利能力、財務風險、營運風險、成長性、自由現金流量比率。 / In recent years, more and more companies tend to finance with other instruments except for seasoned equity offerings. Therefore, my paper attempts to explore if there exists differences in the financial characteristics of the companies who finance with seasoned equity offerings or convertible bonds, and if there exists differences in the financial characteristics of the companies who finance with European convertible bonds or domestic convertible bonds. Besides, I try to find the general situation of the financing behavior in the information and electronic industry in Taiwan. The main empirical results show: 1. The financing behavior of information and electronic industry in Taiwan is suitable for the use of Multinomial Logit model. It means that three financing instruments, seasoned equity offering, European convertible bond, and domestic convertible bond, are independent with each other. 2. As for the information and electronic industry in Taiwan, issuing European convertible bonds is probably the first two choices when discussing the financial characteristics of the firm size, growth, profitability, financial risk, operational risk and the ratio free cash flow. 3. The most influential factor that causes companies to issue European convertible bonds instead of domestic convertible bonds is firm size. And the least influential factor that causes companies to issue European convertible bonds instead of domestic convertible bonds is the ratio of free cash flow.

Yes / This study examines stock market reaction to the announcement of various forms of seasoned issues in China. Our empirical evidence demonstrates that market reactions differ in ways that suggest a difference between management's internal assessment and the market's assessment of the stock price. The market responds unfavourably to the announcement, notably in the case of rights issues and also with regard to open offers. Private placements experience an unfavourable pre‐announcement reaction, which contrasts with the favourable reaction after the event. Convertible bond issues generate positive excess returns consistent with the market's confidence that they can help to align management and shareholders’ interests. Further investigation shows that market reaction is related to factors specific to the issuer and issue by reference to the period immediately surrounding the issue. Specifically, ownership concentration, agency matters connected with equity offerings, investor protection connected with fund allocation and security pricing, and the influence of powerful moneyed interests together provide an instructive insight into market reaction. Institutional inefficiency pertaining to underwriting, auditing, analysts’ forecasts and credit ratings are found to have a weak association with market price, consistent with due public scepticism concerning management and their gatekeepers.

論文名稱：可轉換公司債存續期間之分析 校所組別：國立政治大學金融研究所 畢業時間：九十年度第二學期 提要別：碩士學位論文提要 研究生：陳嘉霖 指導教授：陳松男博士 論文提要及內容： 本研究在分析可轉債的存續期間，在存續期間的衡量上是採用有效存續期間法；而在可轉換公司債的評價上，假設股票價格服從幾何布朗寧運動，無風險利率的變動符合Hu1I-white利率模型，並且考量利率與股票報酬之間的相關性，建立可轉換公司債評價六元樹形圖。 本研究分別針對到期期限長短、價內外程度、股價波動度、利率波動度、股價與利率相關係數及票面利率等六項參數，作可轉換公司債存續期間的敏感度分析，研究結果為：1 加入贖回條款後，可轉債的存續期間高於未加任何條款下的可轉債存續期間。2 加入賣回條款後，可轉債的存續期間低於未加任何條款下的可轉債存續期間。3 加入贖回及賣回候款後，可轉債的存續期間會介於僅含贖回條款與僅含賣回條款的存續期間之中。4 距到期日愈長可轉債的存續期間愈高。5 愈價外的可轉債其存續期間愈高。6 股票波動度愈高，可轉債的存續期間愈低。7 利率波動度增加則可轉債的存續期間上升。8 股票價格與利率相關係數由正至負，可轉債的存續期間上升。9 若贖回權愈小，則票息上升會增加可轉債的存續期間。 關鍵字：可轉換公司債、存續期間、有效存續期間、六元樹、Hull-white、利率模型 / Title of Thesis: Anatomy of the Convertible Bond Duration Name of Institute: Graduate Institute of Money and Banking, NCCU Graduate Date: June, 2002 Name of Student: Chen, Chia-Lin Advisor: Dr. Chen, Son-Nan Abstract: This thesis uses effective duration method to anatomize the convertible bond duration. With the assumptions that stock price follows Geometric Brownian Motion and risk-free interest rate follows Hull and White model, we built a hexanomial tree to value the convertible bond. This thesis analyses the effects of the six parameters . They are maturity date, the ratio of the stock price versus the strike price, the correlation between stock return and interest rate, stock return volatility, interest rate volatility, and coupons. The conclusions include nine points. First, the value of convertible bond duration including call clauses is higher then pure convertible bond duration. Second, the value of convertible bond duration including put clauses is lower than pure convertible bond duration. Third, the value of convertible bond duration including both call and put clauses is between only including call or put clauses ones. Fourth, the longer the time to maturity is, the higher the convertible bond duration is. Fifth, the higher the ratio of the strike price versus the stock price is , the higher the convertible bond duration is. Sixth, the higher the stock volatility is , the lower the convertible bond duration is. Seventh, the higher the interest rate volatility is , the higher the convertible bond duration is. Eighth, the value of the correlation between stock return and interest rate increases from a negative value to a positive one, then the convertible bond duration increases. Ninth, if the value of call right is very small , the convertible bond duration will increase by the increasing of the coupon . Keywords: Convertible Bond, Duration, Effective Duration, Hexanomial Tree, Hull and White Interest Rate Model

由於違約事件不斷發生以及在財務實證上顯示證券的報酬率有厚尾與高狹峰的現象，本文使用縮減式模型與Lévy過程來評價有信用風險下的可轉換公司債。在Lévy過程中，本研究假設股價服從NIG及VG模型，發現此兩種模型比傳統的GBM模型更符合厚尾現象。此外，在Lévy過程參數估計方面，本文使用最大概似法估計參數，在評價可轉換公司債方面，本研究採用最小平方蒙地卡羅法。本文之實證結果顯示，Lévy模型的績效比傳統GBM模型佳。 / Due to the reason that the default events occurred constantly and still continue taking place, empirical log return distributions exhibit fat tail and excess kurtosis, this paper evaluates convertible bonds under Lévy process with default risk using the reduced-form approach. Under the Lévy process, the underlying stock prices are set to be normal inverse Gaussian (NIG) and variance Gamma (VG) model to capture the jump components. In the empirical analysis, we use the maximum likelihood method to estimate the parameters of Lévy distributions, and apply the least squares Monte Carlo Simulation to price convertible bonds. Five examples are shown in pricing convertible bonds using the traditional model and Lévy model. The empirical results show that the performance of Lévy model is better than the traditional one.

隨著資本市場的多元發展，近年來台灣企業發行可轉換公司債之件數倍增，可轉換公司債之所以受到企業青睞，成為愈來愈受歡迎的籌資工具，必有它的獨特之處，而海外可轉換公司債也是公司擴張海外市場的一大助力。本論文的研究目的即在了解台灣上市上櫃公司以國內可轉換公司債(Convertible Bond；簡稱CB)或海外可轉換公司債(Euro Convertible Bond；簡稱ECB)進行融資對其財務績效之影響，並驗證台灣企業發行ECB是否支持Merton(1987)之投資者認可假說。 本論文以1999至2003年間，96家僅發行國內可轉換公司債、70家僅發行海外可轉換公司債、11家同時發行國內與海外可轉換公司債的公司為樣本，實證研究之主要結論如下： 1.公司發行CB或ECB後財務槓桿顯著上升，尤以CB為甚，顯示其財務 風險增加，降低公司財務彈性。若以市值衡量負債比率，則ECB發 行公司在發行前的負債比率較CB發行公司略高，但發行後二年顯著 下降較快。 2.僅發行CB或ECB之樣本公司發行後系統風險皆顯著上升，但同時發 行CB與ECB之樣本，在發行CB後系統風險顯著上升，發行ECB後系統 風險則無顯著變化。 3.在發行公司的績效表現方面，本論文以可轉換公司債發行後的α係 數變化情形為超額報酬之衡量指標，發現三組樣本結果皆顯示CB與 ECB發行後其股價績效表現不佳，前兩組樣本較為顯著。 4.以僅發行ECB組別的70家公司為樣本進行實證，結果顯示發行ECB確 實能增進公司之能見度；但在投資者認可假說方面，台灣市場ECB 的發行並不支持投資者認可假說。故雖然ECB的發行增加公司的能 見度，但財務彈性降低與系統風險增加可能使投資者對公司之未來 前景產生更高之不確定性。 / With diverse development and further integration among international capital markets, more and more companies in Taiwan tend to issue convertible bond for financing in the past few years. In addition, Euro Convertible Bond (ECB) also facilitates firms to expand overseas markets and becomes popular. This study not only focuses on risk and stock price performance changes around convertible bond offerings, but also compares the differences between CB and ECB on research topics. It takes issuing companies that listed in Taiwan Stock Exchange or OTC as objects of study. Moreover, the study tests firm visibility as well as Merton’s investor recognition hypothesis of ECB. Picking 177 samples from Taiwan companies during 1999 and 2003, and I divide them into three groups. 96 firms in the first group only issue CB, 70 firms in the second group only issue ECB, and 11 firms in the final group issue both CB and ECB. According to the empirical results, this study points out several conclusions as follows. First, financial leverage increases after issuing CB or ECB, especially CB firms show more significant increase, and it reduces financial flexibility. Second, systematic risk of companies which only issuing CB or ECB reveal significant increase. However, the 11 firms in the third group show systematic risk that measured with beta increases significantly following CB issuances, but doesn’t change evidently following ECB issuances. Third, I would like to view stock price performance of CB and ECB issuers. The finding shows that relative long-term excess return of three groups all decrease, and the former two groups appear significant drop. Finally, Merton’s investor recognition hypothesis isn’t supported by 70 ECB samples even though issuing ECB could promote firm visibility. This outcome is probably attributed to decrease of financial flexibility and increase of systematic risk.

鑒於近年全球海外可轉換公司債發行檔數大增，然而以此商品為研究主題的文獻並不多，於是決定以此為研究目標。 　　影響海外可轉換公司債的價格因素包括股票價格、匯率、國內利率、國外利率和發行公司的違約機率，因此可買回、可賣回海外可轉換公司債是一個複雜的商品，而評價也較為困難。本文採用三維度二項樹和最小平方蒙地卡羅法建立評價海外可轉債的數值模型。為了更貼近真實世界，本文考量各變數間相關性和動態信用風險；另外，為了使評價更為精準，於股價過程中加入跳躍過程。 　　本文將模型運用至兩檔台灣公司所發行的海外可轉債，發現理論價格傾向於高估，但是理論價格與市價極為接近，尤其當以最小平方蒙地卡羅法評價時。另外本文也針對發行條件和模型中各個變數作敏感度分析，其中重要的是發現股票波動度、股票與匯率間相關係數在海外可轉債評價中扮演重要的角色。 / The number of Euro-convertible bonds issued has highly increased in the early 2010s. However, the related literature is barely found. This paper studies the pricing models of this investment product. Euro-convertible bonds are complex instruments affected by the credit risk of the issuers, the dynamic process of stock prices, the term structure of the interest rate and the movement of the exchange rate in the same time. Accordingly, building the ECB pricing model is a hard work. This paper presents a model considering the dynamic credit risk and jump in stock price process to make valuation more precise. Another advantage of models in this paper is use of stochastic interest rates for both local and foreign so as to make the model more staying with the real world. The other advantage is taking the correlation between each random variables into account. For pricing the Euro-convertible bonds, the numerical methodologies used in this paper are three-dimension binomial tree and least squares Monte Carlo approach. For purpose of assessing the performance of the model, two Euro-convertible bonds issued by Taiwan companies are chosen as samples and the difference between the theoretical price and market price during its issue period are provided. The results demonstrate that in spite of pretty slight overestimation, the least squares Monte Carlo simulation does a better job. In addition, this paper performs several kinds of sensitivity analysis to have in-depth understanding about the models. The consequence shows that the volatility of a stock return and the correlation between stock and exchange rate play a central role in ECB valuations.

影響海外可轉換公司債的因素有許多，包括股價、國內利率、國外利率、匯率，若將時間變數也加入計算，其變動因子高達5階，這種「高維度」的問題已非有限差分法或樹狀方法能處理；且海外可轉債常附有平均式條款、回顧式條款等「路徑相依」性質的選擇權，更是格狀結構數值法(Lattice)難以處理的問題。若使用蒙地卡羅模擬，雖然可以處理高維度及路徑相依的問題，但遇到美式契約時，則會有無法判斷轉換時點的問題，更遑論還必須處理的重設條款或界限型契約。 本論文研究海外可轉換公司債的評價，特點是可以處理其契約中各種可能的複雜條款，本文所使用的最小平方蒙地卡羅模擬，由Longstaff and Schwartz [2000]提出，對於美式契約、路徑相依及高維度問題皆可處理。本文並以Hull and White利率三元樹配適公司債利率符合市場利率期間結構。此外本研究加入海外可轉換公司債評價中最重要的信用風險因素，過去可轉債文獻理論價格大都高於實際市價，這是由於忽略了公司的信用風險溢酬，本文所使用的信用風險模型是由Lando [1998]所提出，特點是不以信用等級作為考量，探討公司特性與所屬產業，並考慮總體因素對違約機率的影響，從市場價格中估計違約密度參數，進而求得信用價差。 本研究對仁寶電腦在2002年所發的ECB做實證研究，比較LSM理論價格與實際市價之誤差，及對Takahashi[2001]所提出之歐式模型做比較，發現本文提出模型之評價結果相當不錯，誤差僅有0.83%；此外並對建華金控2002所發之ECB，探討各種複雜新奇條款對ECB價格的影響，發現市場上嚴重低估了重設條款所提高的價值，而實際市價卻十分接近僅含賣回條款的理論價格。