THEORETICAL BACKGROUND理論背景A wide range of prediction models can be found in literature review. These models use different approaches to evaluate company's performance and predict its failure. A brief chronological and methodological overview of the most important papers is presented below, describing researches that were pioneering (at least for the applied methodology) only at the time and those that are either still widely used or left a mark and provided incentives for other scientists.在文獻查閱中，可以查到各式各樣的預測模型。這些模型使用不同的方法評估公司績效并預測其破產(chǎn)。以下按照年代順序和分析方法分類，簡要介紹一些最主要的理論。這些研究有的在當時是開拓性的（至少應用方法如此），但僅領一時風騷；一些仍在被廣泛使用，或者轉(zhuǎn)瞬即逝，但激發(fā)了其他的科學家。The financial statements analysis dates to the 1920s, when F. Donaldson Brown joined Du Pont Company and in period from 1920 to 1924 developed a model for financial performance measurement. This deductive ratio, known as Du Pont Model analyzes the profitability of a company using traditional financial ratios. It integrates company's profitability and asset management, measuring its liquidity, leverage and efficiency. Return on investment is calculated by interacting different financial ratios from the aforementioned areas. The main strengths of Du Pont model are its simplicity and its linkage to compensation schemes. On the other hand, its main disadvantage is that is based on accounting numbers from balance sheet and income statement which are not reliable because of accrual concept. Du Pont Model remained the dominant form of financial analysis until the 1970s.財務決算分析始于20世紀20年代，F(xiàn).Donaldson Brown入主杜邦公司之后，在1920年到1924年之間建立了一個用于財務狀況評估的模型。這個被稱作“杜邦模型”的演繹比率，利用傳統(tǒng)的財務比率分析了公司的盈利性。它綜合了公司的盈利性和資產(chǎn)管理，測量它的流動性、杠桿和效率。并通過交叉引用以上領域的相關財務比率計算出投資回報率。杜邦模型最大的優(yōu)點是它的簡單和它與薪資規(guī)劃的聯(lián)結(jié)。另一方面，它最大的缺點是它是基于資產(chǎn)負債表和損益表中的會計數(shù)字的。而這些數(shù)字，由于利息觀念的存在，是不可靠的。杜邦模型直到20世紀70年代仍是財務分析的主流。One of the first researches in the area of ratio analysis and bankruptcy prediction, applying statistical methods was conducted by Beaver (1967) in 1966. He applied univariate analysis, using each of 14 accounting ratios separately, and found the difference in financial ratios structure between failed and non-failed companies for as long as five years prior to failure. He concluded that the cash flow to debt ratio was the best single ratio predictor, with a 78% accuracy in predicting bankruptcy. Discussants criticized his model because of the statistical methods used. 最早涉足比率分析和破產(chǎn)預測領域的一位研究者，用的是統(tǒng)計方法。由Beaver（1967）在1966年實施。他應用了單變量分析，分別使用14個會計比率，從而至少在破產(chǎn)的五年之前，就找出了破產(chǎn)與未破產(chǎn)公司之間財務比率結(jié)構(gòu)的差別。他總結(jié)出，現(xiàn)金流與負債比率是最好的單比率預測器——在破產(chǎn)預測中有78%的正確率。而評論者則因為他使用的統(tǒng)計方法而批評他的模型。Altaian (Altaian and Hotchkiss, 2006) precluded this statistical limitation and applied multivariate discriminant analysis to construct his Z-score in 1968, probably the most famous model to the present day. The Zscore model claimed to predict bankruptcy correctly in 95% of the cases one year prior to defaulting, and in 83% of the cases two years in advance and rapidly decreased for longer time observations. However, in the 1980s the theorists, mainly econometricians, began to stress the statistical methodology applied as a major deficiency of the Zscore model. They claimed that linear discriminant analysis follows a normal distribution of financial ratios and equal structure of variance and covariance between paired good and bad companies, which is often not the case in practice. Altaian阿勒坦恩（Altaian阿勒坦恩和Hotchkiss霍奇基斯, 2006）排除了這種統(tǒng)計上的局限，應用多變量判別分析，在1968年建立起他的Z-score理論——也許是現(xiàn)今最有名的模型。Z-score模型宣稱，其提前一年預知破產(chǎn)的準確率在95%，提前兩年預知的正確率為83%，但在更長時間觀測中，正確率會急劇下降。但是，在20世紀80年代，理論家們——主要是經(jīng)濟學家，將Z-score模型中的統(tǒng)計方法視為其重大缺陷。他們認為在分析成對的優(yōu)秀與不良公司時，線性判別分析遵從財務比率的正態(tài)分布，以及方差和協(xié)方差的平衡結(jié)構(gòu)。但現(xiàn)實往往不是如此。