金融市場愈來愈容易發生金融動盪，近年來最嚴重事件的像是全球金融危機，除了造成經濟層面的衝擊外，往往也造成投資人的重大虧損。有鑑於此，政府與投資人更加重視風險管理，若有一可預先衡量系統風險的指標，將能夠使投資人的損失降到最低，甚至能使投資人獲利。此外，政府亦能有效控管風險並預防金融動盪的發生，使金融市場穩定發展。 　　本研究是利用主成分分析，並使用Kritzman, Li, Page and Rigobon(2010)提出吸納比率(absorption ratio, AR)去衡量系統風險。當吸納比率上升時，對應的是較高的系統風險，此時市場的壓力將會增加，因為隱含著風險的來源較一致。但這不代表必然會造成金融動盪，而是表示市場間的緊密連結的程度較高，當市場面臨衝擊時會較脆弱，導致風險傳遞的更快且更廣。 　　本研究的實證是應用至台灣的股票市場，將吸納比率及其變動率與台股大盤月報酬率做比較，實證結果顯示當期吸納比率、當期及前一期的吸納比率之變動率與股票大盤月報酬率有顯著相關，意即在前一期時，吸納比率之變動率可做為下一期的預先風險衡量指標。此外，本篇於文末亦提出未來的研究方向，期望能將吸納比率應用至其他市場，例如債市與房市等，亦希望能夠將此應用至台灣股市的交易策略上，有效地降低投資人的損失並使金融市場發展得以更健全。

企業透明度高低對投資者與企業都有一定影響，對於透明度高企業，投資者比較不會因為資訊不對稱而遭受損失，且能夠有效監督管理者可能有的自利行為；而企業若是透明度較高，也能夠降低在市場募集資金的成本，因此本研究試圖找出對公司透明度能有一定反映程度的指標，藉此作為評價企業透明度參考依據，進一步對研究企業透明度與資金成本的關係有所助益；此外，以我國市場為研究對象，找出會影響本研究找出透明度衡量指標因素，探討可能影響我國企業透明度因素。 本研究以系統風險和一般股價評估模式推論認為系統風險應該對於企業透明度有一定解釋能力，因此本研究以系統風險做為透明度衡量指標，並探討可能影響其因素，可能影響因素則包括研究發展費用比率、公司規模、外資法人持股比率、營業費用比例以及家族企業等因素；由於過去文獻指出系統風險會受營運槓桿與財務槓桿影響，因此本研究將其做為控制變數，此外，股權集中度或許會影響股價的波動，進而影響系統風險，因此本研究也將此做為控制變數。 本研究採用迴歸分析方法研究，研究結果指出，研究發展費用比率以及家族企業對系統風險也就是公司透明度會有所影響，與預期相同，而營業費用比率則無相關，至於外資法人持股比率和公司規模則與預期方向相反，綜觀其原因或許是因為外資在台灣可能以短線進出為主，而規模較大公司又是外資青睞對象而使此兩個指標與預期相反。

風險性資訊之揭露，為目前財務報導中較為缺乏的部分，企業雖有風險管理之政策，然而多數公司對外揭露採取保留態度。因此，使用者難以從財務報導中了解企業對於風險管理的實際狀況，且難以評估該風險狀態對於使用者之影響。本研究針對公司經營層面進行分析，將風險性資訊劃分為營運策略與關係人交易二類加以探討，其中營運策略部分，欲瞭解公司內部經營多角化程度、跨國性程度以及銷貨對象是否會改變公司系統風險；關係人交易之揭露，欲檢視關係人交易之產生，是否為策略聯盟或轉投資之經營型態下所產生之現象，抑或是公司用以進行不合常規交易之管道，以及其與公司系統風險之改變是否有所關聯。本研究以風險性資訊與公司系統風險進行迴歸分析，實證結果發現，公司之跨國性程度對於系統風險具有顯著之關聯性；關係人交易部分，在銷貨及進貨兩項達到顯著之負相關，代表公司可能以與關係人之交易來穩定公司之主要營運，業外的部分反而會提高公司之風險。使用者得以透過該等資訊之揭露，了解企業所面臨的風險，進而評估其投資策略，並加強財務報導對於報表使用者之效用。 / There are very limited disclosures of risk information in financial reporting. Risk management policies exist within the enterprises, however, most enterprises are not eager for disclosure as a result, users are difficult in evaluating risk status of a corporation through financial reporting system. This study divides risk information into: 1) operational strategy and 2) related-parties transactions. The former intends to find out whether the degree of diversification, and multi-national operation, and clientele concentration has an effect on systematic risk or not. The related-parties transactions are intended to test whether they are the result of strategic alliance and reinvestment strategy, or the vehicle for irregular transactions, and their effect on company’s systematic risk. Regression analysis showed that company’s degree of multi-national operation is positively correlated with systematic risk. On the other hand, purchases and sales transactions among related parties transactions are negatively correlated with systematic risk, which suggests that corporations may be engaging in related party transactions to stabilize company’s major operation. The findings of this research suggest that disclosure of company risk management policies in financial reporting improves the quality of accounting information.

本文利用Gravelle and Li (2013)提出之系統重要性指標來衡量國內九家上市金控銀行對於系統風險之貢獻程度。此種衡量方法係將特定銀行之系統重要性定義為該銀行發生危機造成系統風險增加的幅度，並以多變量極值理論進行機率的估算。實證結果顯示：一、系統重要性最高者為第一銀行；最低者為中國信託銀行。其中除中國信託銀行之重要性顯著低於其他銀行外，其餘銀行之系統重要性均無顯著差異。二、經營期間較長之銀行其系統重要性較高；具公股色彩之銀行對於系統風險之貢獻程度平均而言高於民營銀行。三、銀行規模與其對系統風險之貢獻大致呈現正向關係，即規模越大之銀行其重要性越高。在此情況下可能會有銀行大到不能倒的問題發生。四、存放比較低之銀行系統重要性亦較低，而資本適足率與系統重要性間並無明顯關係。 / In this thesis, we apply the measure proposed by Gravelle and Li (2013) to examine the systemic importance of certain Taiwanese banks. The systemic importance is defined as the increase in the systemic risk conditioned on the crash of a particular bank, and is estimated by the multivariate extreme value theory. Our empirical evidence shows that the most systemically important bank is First Commercial Bank, and the CTBC Bank is significantly less important than other banks, while the differences among the remaining banks are not significant. Second, banks established earlier have higher systemic importance; and the contribution to systemic risk of public banks, on average, is higher than the contribution of private banks. Third, we also find out that the size of a bank and its risk contribution have positive relationship. That is, the bigger a bank is, the more important it is. Under this circumstances, the too big to fail problem may occur. Last, the bank which has lower loan-to-deposit ratio will be less systemically important than those with higher ones, while the relation between capital adequacy ratio and systemic importance is unclear.

由於 2007-2009 年金融風暴的發生 , 使得系統風險的研究受到相當大的關 注 , 而此論文也將探討台灣金融業的現況 。 我們根據Adrian et al.(2016) 、 Acharya et al.(2012) 以及 Brownlees et al.(2012)所提出的Delta CoVaR 、 MES 以及 SRISK 等系統風險衡量指標 , 估算台灣金控系統風險的大小 , 以及評 斷台灣系統風險重要金控的排序 。 透過時間序列及橫斷面的分析 , 我們更 將風險趨勢分群 , 或是從相關風險指標來作為監督機構或投資大眾參考的 早期警訊 。 最後 , 我們亦透過追蹤資料模型 , 找出系統風險重要的解釋變數 , 並分析變數的可能影響效果 。 / After the Financail Crisis of 2007-2009, there have been rich research about systemic risk analysis, and this work focus on financial industry in Taiwan. According to Adrian et al.(2016)、 Acharya et al.(2012)and Brownlees et al.(2012), we consider four measures for systemic risk,they are MES、SRISK、Delta CoVaR-DCC and CoVaR-Quantile. We demonstrate how to compare four different measures , and display the ranking of the Systemically Im- protant Financial Institutions (SIFs) based on the resulting SRISK, for Taiwanese holding companies. Finally , we also dicuss the individual and macroeconomic effects on systemic risk by using panel data regression .

本研究以中國大陸上市公司為研究對象，探討股票報酬與公司治理間之關係。此外，為了檢視中國大陸公司治理是否為股票市場上之系統風險，本研究採用學術上廣為使用之四因子模式（Carhart 1997）作為基本迴歸模型，藉由控制住影響大部分股票變異之四因子，純粹探討公司治理指標對於股票報酬之解釋能力。最後，本研究進一步比較各公司治理指標對於股票報酬變異之解釋力相對強弱為何。 實證結果發現： （1）國家股股東持股比率相對較高、董事會規模相對較大、董事長兼任總經 理之公司具有較高股票報酬；而機構法人持股比率相對較高、公眾股股東持股比率相對較高、獨立董事占董事會比率相對較高之公司則具有較低股票報酬。 （2）絕大部分公司治理指標對於超額股票報酬具有顯著影響力，本研究進而推論中國大陸公司治理為股票市場上之系統風險之一。然而，公司治理指標對於提升四因子模式解釋力之程度相當有限。 （3）在原本四因子模式中加入「國家股股東持股比率溢酬因子」、「獨立董 事占總董事人數溢酬因子」二公司治理指標，會比加入「公眾股股東持股比率溢酬因子」、「董事會規模溢酬因子」指標具有較佳之模式解釋力。而在模式中加入「公眾股股東持股比率溢酬因子」、「董事會規模溢酬因子」二公司治理指標又比「機構法人持股比率溢酬因子」指標具有較佳之模式解釋力。 / This study investigates the relation between corporate governance and stock returns in China’s listed companies. Additionally, I apply four-factor model (Carhart 1997) to examine whether China’s corporate governance mechanisms are systematic risks in stock market. At last, I compare the explanation power of excess returns among all corporate governance indexes. I find that: (1) Firms, with higher level of nation ownership, larger board size and dual roles of chairman and managing director, have higher returns; firms ,with higher level of legal person ownership, of public ownership, of independent directors’ ratio, have lower returns. (2) Most Corporate governance indexes have significant impacts on excess stock returns, so we infer that corporate governance in China is one of systematic risks in stock market. However, I also find that corporate governance indexes add few margin contributions to four-factor model. (3) Governance indexes of nation ownership and of independent directors’ ratio have more impact on stock returns than the index of public ownership and of board size. Meanwhile, index of public ownership and of board size have more impact on stock returns than the index of legal person ownership.

本研究透過聯合系統與獨特風險綜合評估違約的強度，假設市場上經濟變數或資訊影響系統之違約強度，然若直接考慮所有經濟變數到模型中將可能會有共線性或維度過高之疑慮，因此透過狀態空間模型來設定狀態變數以及經濟變數之關係並將萃取三大狀態變數分別用以描述市場實質活動面、通貨膨脹以及信用環境。另外，將透過結構式模型來計算獨特性風險大小，當個別潛在的變數低於一定數值將導致個別的違約事件發生。而因布朗運動可能無法描述或校準市場上違約之鋒態以及偏態，將進一步考慮Variance Gamma過程用以更準確描述真實違約狀況。最後透過結合以上兩個風險綜合評估下，考慮一個聯合違約模型來評價信用違約交換之信用價差。 / Systematic and idiosyncratic risks are supposed to jointly trigger the default events. This paper identifies three fundamental risks to capture the systematic movement: real activity, inflation, and credit environment. Since most macroeconomic variables fluctuate together, the state-space model is imposed to extract the three variables from macroeconomic data series. In the idiosyncratic part, the structural model is applied. That is, idiosyncratic default is triggered by the crossing of a barrier. For improvement of the underlying lognormal distribution, we assume the process for the potential variable of the firm follows a Variance Gamma process, sufficient dimensions of which can fit the skewed and leptokurtic distributions. Under the specific setting of combinations of the two risks (the so-called joint default model), we price credit default swaps.

違約事件受到系統性風險與獨特性風險的綜合影響。本研究建構一狀態相依公司信用模型，該模型能反映出系統環境對市場造成的影響與個別公司獨特因子帶來的個別衝擊。 本模型透過從總體環境中萃取出的狀態變數來捕捉系統性變化，另外透過Variance Gamma過程來描繪個別公司的獨特因子帶來的影響。Variance Gamma過程可藉由調整分配的鋒態及偏態來調整布朗運動無法反映出的分配，以更貼近真實的市場訊息。 與縮減試模型相較之下，本模型無需參考信評機構的信用評等資訊，僅依賴市場上公開且透明的資訊，並且與結構式模型相同的是其富有經濟意涵。我們可以透過本模型來同時生成公司流動性危機發生機率與預期流動性危機造成的損失，進而利用本模型評價出個別公司信用違約交換的價格。 關鍵字：信用違約交換；系統風險；獨特性風險；狀態空間模型；Variance Gamma 過程 / Systematic and idiosyncratic risks are thought to affect the default events. This study develops a state-dependent corporate credit model that reflects both systematic movement and idiosyncratic shocks. To capture the systematic movement, the model extracts state factors from macroeconomics data. For the idiosyncratic part, the model applied Variance Gamma Process in depicting the potential variable of the firm by altering the distribution’s skewness and kurtosis. The model contains abundant economic significance as structural-form model does. Comparing to the reduced-form model, it does not rely on the information provided by rating agency but use information that is transparent and public. One can generate a firm’s probabilities of liquidity crisis and expected liquidity shortfalls endogenously and concurrently by employing the model. Credit derivative such as Single-name CDS can be priced under the model.

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.

台灣早期有關系統風險（β）的研究皆指出β不能解釋台灣股票報酬的變異，故控尋更能解釋股票報酬的風險因素為本文的主要目的之一。 本研究分析民國71年7月至85年5月股票上市公司資料（排除金融、保險、及變更交易方式的公司）。因民國79年股價指數從2月的最高點12,495急遽下滑至10月的2,560，故分析上將79年度予以排除。在71年7月至78年12月的時段中，整體市場因素（RM-RF）不能解釋股票報酬的變異。此點發現與台灣早期研究的結論一致。其他變數顯著者僅有與規模有關的因素（SZSMB），或與負債比率有關的因素（DEHML），其中以 SZSMB的解釋能力最強。在民國80年1月至85年5月的時段中，所有模式中整體市場因素（ RM-RF）的係數皆顯著，並且是所有因素中最顯著者。這點發現與前時段（71年7月至78年12月）的結果有很大的不同。其他的變數顯著者，有代表成長機會的BMHML（與淨值市價比有關的因素）、EPHML（與益本比有關的因素）、或CPHML（與營運現金市價比有關的因素），及代表利率結構有關的風險因素TERM（與利率期間結構有關的風險溢酬）、或DFT（與利率違約風險有關的風險溢酬）。其中以（RM-RF）、EPHML、CPHML及TERM的風險組合最能解釋股票報酬的變異。 應用更完整的股票報酬解釋變數，探討股票報酬與盈餘間的關係，亦為本文主要目的之一。經分析以(1)各時段最能解釋股票報酬的因素組合為基礎，計算異常報酬；(2)單獨的以整體市場因素（RM-RF）為基礎計算異常報酬，然後再分別估出盈餘反應比較係數（ERC）比較之。結果顯示，以各時段最能顯著解釋股票報酬的因素組合為基礎的ERC為正的顯著，且其ERC大於只以整體市場因素（RM-RF）為基礎所算出的ERC。 另外，關於盈餘品質假說之測試，經以公司規模大小為虛擬變數放入迴歸式中，結果顯示，代表大公司的虛擬變數之係數時而為正，時而為負，且都不顯著，故盈餘品質假說未獲得支持。 再者，關於成長機會與ERC關係之測試，經以公司成長機會大小為虛擬變數放迴歸式中，結果顯示，代表成長機會的虛擬變數之系數時而為正，時而為負，且大都不顯著，故成長機會大的公司之ERC大於成長機會小的公司之ERC的假說，未獲得實證的支持。 / Earlier studies (Chen 1990; Chiu 1990; and Wang 1992) found that systematic risk (β) could not explain the variance of stock returns in Taiwan. The findings were inconsistent with the Capital Asset Pricing Model (CAPM). One of the major purposes of this paper is to examine the factors that have higher explanatory power of stock returns. To test the hypotheses, this study uses the data of Taiwanese listed companies covering the period from July 1982 to may 1996. The 1990 data are excluded because the stock market index climbed to a record high of 12,495 in February 1990 and then fell sharply to allow level of 2,560 in October 1990. The "crash" might cause structural changes in stock market, so the analyses are conducted separately for the periods before and after the crash, namely the prior-crash period (from July 1982 to December 1989) and the post-crash period (from January 1991 to May 1996). The empirical results show that for the prior-crash period the overall market factor (market returns minus risk free rate, RM-RF) can not explain the variance of stock returns. The findings are consistent with those of previous studies. However, we find that the factor-related to size (SZSMB) and the factor related to debt/equity ratio (DEHML) have significant association with stock returns. Furthermore, SZSMB has higher explanatory power. In contrast, the overall market factor is the most significant factor for the post-crash period. Other factors that are significant consisted of (1) proxies for growth opportunities, including book-to-market equity (BMHML), earnings/price ratio (EPHML), and cash flow/price ratio (CPHML), and (2) the factors related to interest structure, including term structure (TERM) and default risk (DFT). Among these factors, the set of RM-RF, EPHML, CPHML, and TERM explains the variance of stock returns most. Another purpose of this paper is to use the aforementioned findings to study the relationship between stock returns and earnings. The results show that the earnings response coefficients based on the most explanatory factor portfolio of each period are positive and significant, and are greater than those based on the traditional systematic risk (β). The tests for earnings quality hypothesis indicate that the coefficients of the dummy variable proxies for big companies are insignificant. The earnings quality hypothesis is not supported. The tests regarding the relationship between growth opportunities and earnings response coefficients show that the coefficients of the dummy variable proxies for high growth companies are unstable. The hypothesis that the earnings response coefficients of high growth companies are greater than those of low growth companies is not supported by empirical evidence.