Zongming Ma Abstract: The financial crisis in 2008 raised the concern of many practitioners and academics about the validity of the capital asset pricing model. In this paper, we use the data (ranged in ten years around the 2008 financial crisis) from ten industries to test the validity of the capital asset pricing model. Our results show that the model is not effective in these ten years. However, the 2008 financial crisis had an impact on the model: investors are more averse to risk after the financial crisis than before. In this study, we find that Beta (financial elasticity) is not the only factor that can explain the excess return; more factors should be added in the model to predict the excess return of the portfolio on the financial market. Keywords: CAPM, Financial Crisis
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1. Introduction
The capital assets pricing model (CAPM) is commonly used in the field of finance. The CAPM model was first introduced by Jack Treynor (1961, 1962) and William Sharp (1964), and then was interpreted and developed by John Lintner and Jan Mossin from different views and perspectives. Based on the Markowitz’s Portfolio Theory, beta is defined as covariance of an asset which is related to market index. “The Sharpe-lintner-Mossin CAPM has been advanced to explain the relationship between the risk of a security and the equilibrium expected rate of the return required by investors to induce them to hold the outstanding supply of that security"(RogerA.Morin,1980). The CAPM model is still the core of the theory of financial investment. Since CAPM was introduced, many practitioners and academics have continued to research the model. They engaged in testing the capital asset pricing model and modifying it. Roll (1977, 1978) tested the model and Ross (1976) introduced ATP (Arbitrage Pricing Theory) which was modified from CAPM. In order to
References: In Jensen, M. C., & Conference on Modern Capital Theory. (1972). Studies in the theory of capital markets. New York: Praeger. Fama, E. (February 01, 1993). Common risk factors in the returns on stocks and bonds. Journal of Financial Economics,33,1, 3-56. Roger A.Morin(1980),"Market Line Theory and the Canadian Equity Market,"Journal of Business Administration 12,no.1. Roll, R., & Ross, S. A. (2003). On the Cross-Sectional Relation between Expected Returns and Betas. In R. R. Grauer (Ed.) , Asset pricing theory and tests. Results of time-series regression test on CAPM First-regression(before2008) First-regression(after2008) αi βi 0.53147*** (0.07745) 1.2897*** (0.1188) 0.9284*** (0.0708) 0.7238*** (0.1496) 1.7613*** (0.1011) 1.1856*** (0.1056) 0.95034*** (0.08716) 0.61094*** (0.08071) 0.6601*** (0.1091) 0.95115*** (0.06204) 0.68747*** (0.05794) 0.68747*** (0.05794) 1.22535*** (0.05412) 0.894706*** (0.110162) 0.98584*** (0.07347) 0.94925*** (0.08018) 0.79503*** (0.07759) 0.64905*** (0.0978) 0.5544*** (0.08743) 1.334*** (0.0783) R2 -1.95536*** (0.28704) 0.3826 (0.31772) 0.49234 0.8292 -2.6467*** (0.4401) 0.3826 (0.31772) -0.01167 0.8292 -1.7984*** (0.2624) 0.6935 (0.29675) 0.009897 0.9465 -1.2328* (0.5546) 0.2354 (0.60406) 0.52608 0.6946 -2.794*** (0.3749) 0.7996 (0.40288) 0.20673 0.8613 -2.8931*** (0.3913) 0.624 (0.43968) 0.35848 0.8286