CAPM Assignment Example | Topics and Well Written Essays - 1000 words

CAPM - Assignment Example CAPM has theoretical limitation, which include impractical assumptions and instability of the beta values. The Arbitrage Pricing Model and Rolls have criticized the theory indicating that it may be unreliable and invalid. This study will examine the theoretical limitations and criticisms of the theory. Theoretical Limitations of the Theory The theory argues that all investors are risk avoiders and that the returns are normally distributed (Ma, 2011). This is not the case because investors are normally risk takers who are willing to make huge returns when their predictions favor them and lose when they fail. Assuming that returns are normally distributed is also unfounded because investors are not usually sure of the yields on their assets (Ma, 2011). The assumption that assets are free from risk is also unrealistic because it is hard to find such stocks in the real world. The theory argues that short-term securities offered by the government are free from hazards because the state as sures investors certain returns on the assets. This is not the case because the risk on the assets is in the form of inflation, which is the instability of prices in the market (Ma, 2011). Inflation leads to the loss of value of money, and this means that, assets also lose their worth when prices rise in the economy. Since money loses its value then it means that investors face the risk of lower returns when their stock matures. For example, when the state pays 10% on its short-term bonds then inflation rises in the country by 2%, investors get 8% returns on their securities in real terms. This means that investors face the risk of inflation, which reduces their earnings. This also indicates that the CAPM model is applicable in an ideal world, an occurrence that is impossible (Ma, 2011). Roll’s Critique of CAPM Roll criticizes the validity of the Capital Asset Pricing Model equation. The equation is as indicated below: E(Ri) =RF +?i [E(RM) - RF] Where E(Ri) represents the yie ld on security i. RF is the risk free rate of return. Bi is the market risk that security i faces. Roll’s first critique was that the model could not be tested using current data because it is constructed based on historical data. The impossibility of testing the model arises from the fact that it is based on market values of stocks, real estates, jewelers, and labor. Rolls argue that it is impossible to find the market value of this portfolio because no accurate data of these factors exists in reality. Thus, Roll argues that the CAPM cannot be proven right or wrong because of the impossibility of getting accurate data (Ma, 2011). Roll argues that economic models should be easy to test using future data because they simplify the real life. However, according to him, CAPM is complex because of the inability of being tested using future data, and this makes it unreliable. Roll also postulates that it is impossible to get efficient stocks whose values and rates of return have li near relationships ideally (Ma, 2011). Therefore, Rolls argument generally argues that CAPM is unreliable because it has never been tested using real data, and it is still impossible to do so because of uncertainty of prices, which is common in the real world. Arbitrage Pricing Model (APM) The APM addresses the weaknesses of CAPM by doing away with the assumption that the