【正文】 an optimal capital structure, the decision is often obscured by practical limitations to the theoretical base. In order to be useful to practicing managers, policies and decision techniques need to be efficiently acplished and based on available information. This paper provides that practical framework. We recount a simplified theoretical base for capital structure, highlight some of the problems encountered when applying the theory to reality, and suggest a framework for practical managerial decisions about capital structure.The current issue and full text archive of this journal is available at This exposition is especially useful in undergraduate business curricula, in particular for finance majors considering professional management as a career.2. Traditional capital structure theoryCapital structure theory was initially formed in a series of articles by Modigliani and Miller (1958, 1963). Under conditions identified by a long list of simplifying assumptions, they provided the foundation for an understanding of the differences between unlevered and levered firm values. Although many of the assumptions were unrealistic, the initial model served as a point of deviation as assumptions were relaxed. Most of the assumptions involved either tax structure or risk structure simplifications.The typical capital structure theory exposition has bee known since that time as a tradeoff theory. Tradeoff theory provides an exposition of the benefits of prudent debt use and the dangers of excessive debt use. The solution variable is the proportion of debt in the firm capital structure, the debt ratio. Although the model has a high level of mathematical sophistication and plexity, a simplified result can be formed by observing two of the main features of the model.The first feature to consider is that, since interest expense is tax deductible, then the more debt used by the firm, the more wealth created via lower tax payments. This is called a tax shield, which has an evident cash value to shareholders, a ready and apparent gain to leverage. As a firm uses more and more debt, the tax shield will bee larger and larger, adding value to the firm. Graphically, this is shown in Figure 1. Figure 1 shows that the initial value of the firm is the value of the equity, since at zero debt, the firm is financed totally by equity. As debt is added to the capital structure (the debt ratio increases), the value of the firm rises proportionally because of the tax shelter benefit. In the graph, this is represented by the green upward sloping line.The second feature is that risk increases as the firm adds debt to the capital structure. Debt would be very beneficial at low levels, since it is so much cheaper and provides the tax shield. But as large proportions of debt are taken on, the firm begins to be financially distressed by trying to meet interest payment obligations. The more debt the firm adds,FirmvalueValue of debttax shelterFinancial distresscostsDebt ratiothe more financially distressed it bees, less able to service interest expenses for extreme debt levels. Financial distress costs would include higher required returns from both creditors and shareholders, as well as costs directly involved with avoiding bankruptcy and costs associated with financial distress and bankruptcy. These costs, at some point, begin to offset the positive effects of the tax shield, and the value of the firm begins to level off, and then to decline. This is represented in the graph by the red line. Recognizing just two of the characteristics of debt use (tax shelter and financial distress), the idea of the capital structure decision begins to take shape.The graph seems to suggest that there is some debt level that is optimal ([D/A] *)。但只有在收購能夠使公司資本結(jié)構(gòu)趨向最優(yōu)，收購項目有利可圖，并且最終使公司價值得到提高的情況下，這樣杠桿收購才有意義。經(jīng)營風險對鋼鐵產(chǎn)業(yè)上市公司資本結(jié)構(gòu)的影響是顯著的。鋼鐵產(chǎn)業(yè)上市公司的固定資產(chǎn)價值普遍較高，可抵押性較強，因此應充分利用自身優(yōu)勢，在條件允許的情況下通過發(fā)行可擔保公司債券進行融資。證監(jiān)機構(gòu)應該出臺相應的法律，促進上市公司信息公布及時、有效、公開和透明，努力減少上市公司因信息不對稱導致的代理成本，以及交易困難。所以公司內(nèi)部治理機制的好壞成為了影響資本結(jié)構(gòu)的重要原因。事實上，從融資成本上講，債券融資比股權(quán)融資更優(yōu)越。所以在對于以上的四個指標和整體行業(yè)做完分析后我們從以下幾個方面對鋼鐵行業(yè)的資本結(jié)構(gòu)進行優(yōu)化。同時對比來看對于在整個鋼鐵行業(yè)處于業(yè)績不太理想的兩家公司的此指標都比較低這說明在企業(yè)中負債所占的比重較大，所以行業(yè)的風險比較大同時不容易得到投資人的信任。這兩個比率從不同的側(cè)面來反映企業(yè)長期財務狀況，股東權(quán)益比率越大，資產(chǎn)負債比率就越小，企業(yè)財務風險就越小，償還長期債務的能力就越強。所以根據(jù)附表A表三中的數(shù)據(jù)，我們進行了簡單的統(tǒng)計整理出表5，從表5中我們可以看出，—，屬于在行業(yè)平均值左右的合理波動，由于鋼鐵行業(yè)的特殊性，在我國鋼鐵行業(yè)中企業(yè)為了正常的生產(chǎn)和經(jīng)營無法達到較低的長期負債率。所以從上述的分析中我們可以簡單地分析和總結(jié)出，對于我國鋼鐵行業(yè)來講，要想達到一個穩(wěn)定合理的資本結(jié)構(gòu)狀態(tài)，我們就需要降低短期帶息負債比率的數(shù)額，但是如果一個企業(yè)的短期負債過少，那么企業(yè)的流動資金相對而言也會比較少這樣會影響企業(yè)的盈利性，所以據(jù)上述表3和表4顯示，要想達到合理狀態(tài)那么短期帶息負債比率需要維持在行業(yè)平均值附近或略低于行業(yè)平均值。 帶息負債比率=帶息負債總額/負債總額*100%帶息負債總額＝短期借款＋一年內(nèi)到期的長期負債＋長期借款＋應付債券＋應付利息此指標的主要目的是衡量在負債中不同的組成部分所占的比重，這個比率越低，證明企業(yè)舉債成本越低，相對來說利潤也就會提高。表1 0812年鋼鐵行業(yè)資產(chǎn)負債率分布情況表　20082009201020112012332346556798765101314121043456行業(yè)平均值表2 0812年六家公司資產(chǎn)負債率表20082009201020112012寶鋼鞍鋼首鋼攀鋼鋼釩撫順特鋼西寧特鋼從附表A表一中我們可以看出,所以根據(jù)附表A表一中的數(shù)據(jù),我們將資產(chǎn)負債率不同的分布情況編織出表1，從表中可以明顯的看出行業(yè)中大部分公司的資產(chǎn)負債率都分布在行業(yè)平均值的左右。這個指標反應的是，企業(yè)資產(chǎn)中有債權(quán)人所提供的百分比究竟有多少。（二）分析樣本的選擇在分析總結(jié)完該行業(yè)特點后，系統(tǒng)分析行業(yè)資本結(jié)構(gòu)變化過程，找出影響資本結(jié)構(gòu)的因素，就對優(yōu)化資本結(jié)構(gòu)具有重要的意義。3．鋼鐵行業(yè)中競爭激烈鋼鐵行業(yè)的生產(chǎn)圍繞高質(zhì)量，低成本，多品種的競爭日益激烈，隨著我國現(xiàn)代化和工業(yè)化的發(fā)展，市場對鋼鐵行業(yè)生產(chǎn)的品種的質(zhì)量的要求越來越高，鋼材的高質(zhì)量高技術(shù)集中表現(xiàn)在板，管，帶上。所以不同的發(fā)展周期由于產(chǎn)生不同的經(jīng)營風險而導致資本結(jié)構(gòu)的差異。從所有者的角度看如果企業(yè)股權(quán)比較分散，那么可能更多的采用權(quán)益資本籌資，這樣可以使企業(yè)的風險減小。同時一個企業(yè)的成長性也是不可忽視的因素，成長率越高的企業(yè)可以采用高負債的資本結(jié)構(gòu)，這樣在企業(yè)能負擔的比重下高負債率可以產(chǎn)生更多的盈利，有利于企業(yè)的經(jīng)營和發(fā)展。在1958 年，美國兩位學者Miller 和Modigliani 提出了著名的MM 理論。因為現(xiàn)階段資本結(jié)構(gòu)作為反映企業(yè)經(jīng)濟實力、風險程度、經(jīng)濟效率高低的重要指標。與此同時，粗鋼消費量持續(xù)增長，%。16附錄A11（二）從上述分析的財務指標出發(fā)的優(yōu)化措施2 企業(yè)資產(chǎn)結(jié)構(gòu)的多樣性2（二） 資本結(jié)構(gòu)的影響因素如在文中涉及到抄襲或剽竊行為，本人愿承擔由此而造成的一切后果及責任。4 鋼鐵行業(yè)中的競爭激烈11（一）從微觀和宏觀兩個角度分析13五、結(jié)語“十一五”期間，我國粗鋼總產(chǎn)量超過26億噸，是“十五”。鋼鐵行業(yè)飛速迅猛的發(fā)展是和