William Paul Bell Queensland University Researcher

Why is mainstream economics not a social science but ideological mathematics?

Posts Tagged ‘capital asset pricing model

Capital Asset Pricing Model (CAPM) and Efficient Market Hypothesis (EMH) Contributing to the Global Financial Crisis (GFC)

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The Efficient Market Hypothesis (EMH) and Capital Asset Pricing Model (CAPM) are a framework and standard financial tool, respectively. Together, they provide a worldview for financiers and determine their decision-making in the financial markets.

Fama (1965; 1970) introduces the EMH in three market efficiency levels: a strong level where all relevant information regarding a stock is fully reflected in its price; a semi-strong level where all publicly available information is reflected in its price; and a weak level where current prices reflex all past history of the prices.

Fama and French (2004, p. 25) note that CAPM of William Sharpe (1964) and John Lintner (1965) marks the birth of asset pricing theory (resulting in a Nobel Prize for Sharpe in 1990). Four decades later, the CAPM is still widely used in applications, such as estimating the cost of capital for firms and evaluating the performance of managed portfolios. It is the centerpiece of MBA investment courses. Indeed, it is often the only asset pricing model taught in these courses. Read the rest of this entry »

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Hormonal Male Traders producing a Momentum Effect contrary to the Efficient Market Hypothesis and Rational Choice

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Coates and Herbert (2008) study the role of the endocrine system in financial risk taking in a group of male traders in London. They find a positive relationship between a trader’s testosterone level and his daily Profit and Loss (P&L) and between his cortisol level and financial uncertainty, being measured by variance of economics returns and expected variance of the market. They note that rational choice is affected by the levels of the hormones. The more profits the trader made relative to his daily average the higher his testosterone became. Heightened testosterone increases a trader’s preference for risk. The process has a positive feedback, producing a financial variant of the “winner effect”. Additionally, short periods of high volatility increase a trader’s cortisol levels, which increase his motivation and his ability to focus, producing a euphoric feeling. However, prolonged period of elevated cortisol levels produce selective attention on mostly negative events and anxiety, reducing a trader’s preference for risk. Even if the number of traders is small, these hormonal effects could reinforce the momentum effect and cause markets to deviate from rational choice and the predictions of the Efficient Market Hypothesis (EMH). Read the rest of this entry »