本文的主要目的，是找出一個簡單且有效的方法，預測台灣的股市報酬。比較許多不同的研究後，我發現無論面對多重共線性亦或變動要素結構等問題，主要要素模型(Principal Components Analysis)都可以表現地比其他模型優異。因此，在此篇文章中，我結合了資產訂價理論(Asset Pricing Theory)與主要要素模型的概念，來預測台灣八大產業股票指數的報酬。分析結果顯示，雖然主要要素模型在本文中的預測表現不如預期，但是整體仍優於隨機漫步(Random Walk)的預測。這意味著，主要要素模型對台灣股市的預測，可以在某種程度上推翻效率市場假說(Efficient Market Hypothesis)。 / The original purpose of this paper is to find a useful and simple way to forecast the return rates of Taiwan stock market. Comparing different empirical studies, I found that no matter with problems of multicollinearity or changing factor structure, the Principal Components Analysis (PCA) can usually outperform other models. Therefore, I combined the concepts of Asset Pricing Theory (APT) and PCA, to predict the movements of eight industrial indexes return rates of Taiwan stock market. The analysis indicates that, although PCA forecasting results couldn’t be very impressive in Taiwan stock market, it still can perform better than Random Walk Regression. That means the forecasting results of PCA to Taiwan stock market can overthrow the Efficient Market Hypothesis (EMH), which represents the trends of stock return rates are unpredictable, to some extents.

公司治理的研究,其主要的目的是了解董事會組成,董事會規模,外部董事, 董事及CEO薪酬誘因,CEO改組,外部大股東,外國股東,機構投資人,控制權和股權集中性,併購,法律制度及執行,法源…等變數對以ROA,ROE,會計盈餘,Tobin’s Q和股市報酬率所代表的公司績效之影響。與公司治理有關的重要指標包括股份控制權,現金流量權,董監事席次的控制權,控制權與股權的偏離,次大股東,金字塔結構,交叉持股,優先投票權,外部董事比例等。 本論文共計8章40節,引述國外文獻約500篇並由國際公司治理的實證結果來探討我國五家金控：開發金、台新金、復華金、富邦金、兆豐金的公司治理,最後提出九點結論和建議。

已實現投資報酬率與無風險利率之差、被稱為超額報酬，而股票的預期報酬率超過無風險利率的部份則為股票風險溢酬，是許多資產評價模型的重要依據，例如資本資產定價模型。有不同的理論架構解釋說明風險溢酬值，例如；股票風險溢酬的迷思、短期損失的憎惡、生還存留因素和回歸與偏離平均值等等。 研究台灣股市的超額報酬與股票風險溢酬，有助投資大眾和企業理性面對股市的預期報酬和風險，對台股才有合理的期望報酬值。分析1967年迄2003年的台灣金融市場，計算過去37年長期的幾何平均年報酬率，以臺灣證券交易所發行量加權股價指數為台股市場報酬率，已實現台股實質年報酬率為6.71%。無風險報酬率使用第一銀行的一年期定期存款利率，實質台幣存款年利率為3.07%，消費者物價指數年增率則為4.80%。以年資料計算的台股實質超額報酬，算術和幾何值分別為12.48%和3.63%(年)，計算月資料算術平均和幾何平均值分別為0.77%和0.25%(月)。過去37年長期的台股超額報酬現象未較歐美市場的情況更加明顯，也比一般市場的預期報酬率低。 因資料取得的限制、台股的理論超額報酬方面，1991年迄2003年的近十三年來，經固定股利成長模式和盈餘成長模式的兩種計算方式，台股的實質超額報酬分別為 0.6%和-4.3%，此時期台股的投資報酬率比起台幣存款並不突出、且是低超額報酬。同期的已實現的實質超額報酬值；算術平均1.69%和幾何平均-3.35%。評估目前台股風險溢酬，將十分接近過去37年長期歷史資料得到的超額報酬數值，算術年均值為12.48%(年)和0.77%(月)，幾何平均分別為3.63%(年)和0.25%(月)，低風險溢酬是當前台灣股票市場的一般現象。 / The difference between the observed historical investment return and the risk-free interest rate is the excess return. The equity risk premium, ERP is the expected rate of return on the aggregate stock market in excess of the rate of risk-free security. ERP is one of important factor of many asset-pricing models, including Capital Asset Pricing Model, CAPM. There were many theories and factors to explain the equity risk premium; equity premium puzzle, myopic loss aversion, survivorship bias, mean reversion & aversion and etc. Studying the value of Taiwan equity excess return and risk premium is fundamental for investors and institutions evaluating the expected market investment return and risk. Analyzing the data from year 1967 to 2003 for thirty-seven years long holding period, Taiwan Stock Exchange Capitalization Weighted Stock Index as Taiwan stock market return, the realized real return was 6.71%. One-year bank time deposit rate as NT dollars risk-free asset rate and real interest rate was 3.07% and consumer price index, CPI annual growth rate was 4.80%. The historical real yearly excess return was 12.45% for arithmetic mean and 3.63% geometric mean; the historical real monthly excess return was 0.77% for arithmetic mean and 0.25% geometric mean. Taiwan realized equity excess returns were not higher than the returns in the developed countries and were also lower than the market's expectation. Due to the limits of available data, the theoretical equity excess returns that were calculated on two theoretical models; Constant Growth Dividend Discount Model (dividend yield model) and earnings yield model were 0.6% and -4.3% from year 1991 to year 2003. Comparing the same period of historical realized excess returns of 1.69% for arithmetic mean and -3.35% geometric mean, Taiwan stock market returns were not spectacular. The current equity risk premium of Taiwan stock market is low and should be near the level of the long historical realized equity excess return.