權益比率(Equity Ratio)是將股東權益總額除以資產總額之比值，對公司而言該比率代表自有資金佔所有資金來源的比例。我們計算1988年到2008年美國與台灣非金融民營企業權益比率，發現美國權益比率在這段期間較台灣高。文獻上探討資本結構問題多以公司治理角度出發，並未考慮個人風險態度與金融環境。因此，我們建立一模型來了解決定權益比率的因素。該模型包含風險厭惡程度係數與金融環境並具有以下特徵：(1)權益比率由個人資金分配到廠商的份額(簡記為St)決定；(2)權益比率(及St)與存款準備率呈現同向變化；(3)風險趨避程度、投入廠商資金報酬率的變異、存款利率三者與權益比率(及St)反向變動；(4)資金投入廠商期望報酬率與權益比率(及St)的關係為同向變動。最後，我們採用2000年到2008年的資料，利用OLS-CUSUM test 檢定結構性轉變，確認美國與台灣企業權益比率在2000年到2008年皆穩定，可各自代表其恆定狀態(Steady State)。因此，我們以美國及台灣2000-2008年的平均值作比較發現變數變動的方向和模型預測一致(存款利率及投入廠商資金報酬變異除外)，其中以風險趨避程度差異最為明顯，故美國權益比率大於台灣權益比率的原因與風險厭惡程度有關。

Baltensperger, E. (1980),“Alternative approaches to the theory of the banking firm”, Journal of Monetary Economics, Vol. 6, pp. 1-37

Bernanke, B. and Gertler, M. (1989),“Agency costs, net worth, and business fluctuations”, The American Economic Review, Vol. 79, No. 1, pp. 14-31

Bodie, Z., Kane, A., and Marcus, A. J. (2002),“Investments”, McGraw-Hill/Irwin

Brown, R. L., Durbin, J., Evans, J. M. (1975), “Techniques for testing constancy of regression relationships over time”, Journal of the Royal Statistical Society, B, 37, pp. 149-163

Chow, George (1995),“Portfolio selection based on return, risk, and relative performance”, Financial Analysts Journal, Vol. 51, No. 2, pp. 54-60

Elyasiani, Elyas (1983),“The two product banking firm under uncertainty”, Southern Economic Journal, Vol. 49, No. 4, pp. 1002-1017

Frank, M. Z. and Goyal, V. K. (2003), “Testing the pecking order theory of capital structure”, Journal of Financial Economics, 67, 217-248

Graham, J. R. and Harvey, C. R. (2001),“The theory and practice of corporate finance: evidence from the field”, Journal of Financial Economics, Vol. 60, pp. 187-243

Jensen, M. C. and Meckling, W. H. (1976),“Theory of the firm: managerial behavior, agency costs and ownership structure”, Journal of Financial Economics, V. 3, No. 4, pp. 305-360

Levy, H. and Markowitz, H. M. (1979),“Approximating expected utility by a function of mean and variance”, American Economic Review, Vol. 69, pp. 308-317

Lu, Shu-Shiuan (2010),”The role of capital market efficiency in long-term growth: a quantitative exploration”, National Tsing-Hua University, working paper

Markowitz, H. M. (1952),“Portfolio selection”, Journal of Finance, Vol. 7, pp. 77-91

Marsh, P. (1982),“The choice between equity and debt: an empirical study”, The Journal of Finance, Vol. 37, No. 1, pp. 121-144

Miller, M. H. (1977),“Debt and taxes”, The Journal of Finance, Vol. 32, No. 2, pp. 261-275

Modigliani, F. and Miller, M. H. (1958),“The costs of capital, corporation finance and the theory of investment”, American Economic Review, Vol. 48, No. 3, pp. 261-297

Modigliani, F. and Miller, M. H. (1963),“Corporate income taxes and the costs of capital : a correction”, American Economic Review, Vol. 53, No. 3, pp. 433-443

Myers, S. C. and Majluf, N. S. (1984),“Corporate financing and investment decisions when firms have information that investors do not have”, Journal of Financial Economics, Vol. 13, pp. 187-221

Myers, S. C. (1984),“The capital structure puzzle”, Journal of Finance, 39, 575-592

Ploberger, W. and Krämer, W. (1992), “The CUSUM test with OLS residuals”, Econometrica, 60, pp. 271-285

Sealey, C. W. Jr. and Lindley, J. T. (1977),“Inputs, outputs, and a theory of production and cost at depository financial institutions”, The Journal of Finance, Vol. 32, No. 4, pp. 1251-1266

Shyam-Sunder, L. and Myers, S. C. (1999),“Testing static tradeoff against pecking order models of capital structure”, Journal of Financial Economics, 51, 219-244

Steinbach, M. C. (2001),“Markowitz revisited: mean-variance models in financial portfolio analysis”, SIAM Review, Vol. 43, No. 1, pp. 31-85

Swank, J. (1996),”Theories of the banking firm: a review of the literature”, Bulletin of Economic Research, Vol. 48, Issue 3, pp. 173-207

Zeileis, A., Leisch, F., Hornik, K., and Kleiber, C. (2002),“strucchange: An R package for testing for structural change in linear regression models”, Journal of Statistical Software, 7(2), 1-38.