股份有限公司為近代社會最具開創性與影響力之組織型式，其股權之評價亦相對複雜且重要。本文首先從公司組織型式所具有之性質出發，探討股權價值之來源，並結合財務會計理論體系及財務報表資訊特性，將調適選擇權與重整選擇權概念納入基本評價模式中。其次將折溢價因素部份由調適價值中獨立出來，俾便於將此模式與基本之股權評價資訊一帳面價值相結合，以發展出一整體之會計基礎評價模式。此模式將股權價值表示成股權之帳面價值(B)加上四個調整項，包括：(1)來自超額盈餘資本化之價值(E)；(2)公司可選擇調整營運方式、資產組合、或進行清算之淨調適買權價值(A)；(3)來自有限責任制之重整買權價值(C)；及(4) 其他影響股權價值之折溢價因素部份(D)。其中折溢價因素部份主要來自資產之調適價值與帳面價間之差額（調適溢價），本文另透過產品生命週期之觀念，找出影響折溢價幅度之可能原因，並指出因為股權價值中存在此折溢價因素部份，使股利政策對公司之股價有所影響。

惟本模式中包括兩種選擇權價值及折溢價因素部份，各公司依其性質不同而有相當大之差異，本文無法明確加以個別估計出。僅能採用分析具有此等價值部份時股權價值所應有之性質，再以大樣本資料加以測試之方式，來提供此模式有效性之間接支持。故本研究依據此模式所預期之主要特性，提出六個研究假說，以我國股市之資料加以實證，來測試該模式對股權價值水準與變動幅度的解釋力，及對折溢價因素部份之水準與變動幅度的解釋。實證結果如下：

1.在股權價值水準方面：假說一（及假說二）所預期「在給定帳面價值（預期盈餘）下，股權價值為期望盈餘（帳面價值）的遞增凸函數」，皆獲資料支持，且就我國股市而言，折溢價因素部份具相當之影響力，顯示以帳面價值為基礎之評價模式應將此部份納入。

2.在股權價值變動幅度方面：由於公司具有調適選擇權，假說三主張：當公司之股權價值主要來自盈餘資本化價值時，其盈餘對股價變動之影響相對大於股權價值主要來自帳面價值者。此亦獲得迴歸結果之支持。假說四則針對艱困公司來測試股東所具有之重整買權價值，實證結果大致支持：艱困公司之盈餘對股權價值的影響相對小於一般公司；且其股價對赤字之反應相對小於對正盈餘之反應。

3.在折溢價因素部份方面：假說五以封閉型基金為對象，探討股利發放對折價幅度減少之效果。實證結果顯示，基金所發放之現金股利額較高時，其折價減少幅度顯著較大，與假說五之預期一致，此可提供股利攸關論之若干支持。最後，假說六探討主力產品處於成長期之公司，其溢價幅度是否大於主力產品處於成熟期之公司。經控制資產調適溢價效果後，檢定結果亦與假說六之預期一致。

整體而言，本研究無論在理論上或實證上，皆指出會計資訊對股權評價具攸關性。希望經由本文之提出，可提供有關股價行為及股利政策攸關性之若干思維空間。

The corporate form of organization is the most creative and influential entity in the modern society, but the valuation of its equity value is relatively more complex and important. In order to investigate the sources of equity value, the paper starts from the attributes of corporation. Combining the theoretical systems of financial accounting with information characteristics of financial statement, the paper includes the concepts of net adaptation option value and restructured option value to form the basic valuation model. Next, the paper separates the discount/premium factors from the adaptation value to combine the basic valuation information of equity, book value, and develops and integral accounting basic valuation model finally. The model characterizes the equity value in terms of book value (B) and four adjustments:(1) the value of capitalization of excess earnings (E); (2) net adaptation or liquidation (A); (3) the restructured value of call option from the system of limited responsibility (C); (4) other discount/premium factors affecting equity value. The discount/premium factors mainly come from the difference between assets' adaptation value and book value. By the concept of product life cycle, the paper points out some causes affecting the magnitude of discount/premium factors. Due to the discount/premium factors in the equity value, the dividend policy affects the share price.

Because we have two option values and discount/premium factors in the model, there are material differences among companies due to their specific nature, so we are unable to estimate the values and factors explicitly. What we can do is to analyze the nature of share price impounding such option value and test it by large sample, such that we can provide indirect support of the validity of the model. Next, the paper tests the explanatory power of valuation model to the level of equity value and the degree of variation by the data of listed company in Taiwan. By the empirical test, we can understand the dividend policy implication of the discount/premium factors.

We have six hypotheses and their results in the follows. Hypothesis one (H1) maintains that the market value of equity is the increasing convex function of expected earnings given the book value, although the hypothesis is supported, the discount/premium factors have significant influences for our stock market price, and it implies the valuation model based on book value should include the discount/premium factors. Hypothesis two (H2) proposes that the market value of equity is the increasing convex function of book value (adaptation value) given the expected earnings. H2 is supported by the data.

The hypothesis three and four are related to the definition of the relationship between changes in equity value and earnings. Due to the existence of adaptation call option, hypothesis three (H3) claims that the effect of earnings on changes in share price is larger when the equity value mainly comes from capitalization of excess earnings than that from book value. The regression results support H3. Using the financially distressed companies, the paper tests hypothesis four (H4): in contrast to the normal company, the effect of earnings upon equity value is smaller for the distressed company with lower book value(or successive operating loss)and the effect of deficit(negative earnings)upon share price is also smaller. Roughly speaking, the hypotheses are supported.

The hypothesis five and six are related to the other discount/premium factors that are more difficult to define in the equity value. Hypothesis five (H5) investigate the effect of dividend distribution upon the decreases in discount magnitude by the closed-end mutual fund and is supported. Finally, hypothesis six (H6) examines whether the premium magnitude is larger for the company whose core products are in the period of introduction of growth than for the company whose core products are in the period of maturity or steady growth. The hypothesis is supported and consistent with the expectation.

In conclusion, the paper demonstrates that accounting information is relevant to the valuation of equity value, either in theory in or on empirical results. Hopefully, the paper could provide some avenues to consider the behavior of share price and the relevance of dividend policy.