Asset Pricing and the Intertemporal Risk-Return Tradeoff

Abstract

The intertemporal risk-return tradeoff is the cornerstone of modern empirical finance and has been the focus of much debate over the years. The reason for this is because extant literature cannot agree as to the very nature of this important relation. This is troublesome in terms of academic theory given that it challenges the notion that investors are risk-averse agents and is furthermore troublesome in practice given that market participants expect to be rewarded with higher expected returns in order to take on higher risks.
The motivation for this thesis stems from the conflicting and inconclusive empirical evidence regarding the risk-return tradeoff. Through each of the chapters, it sheds new light on possible reasons as to why extant studies offer conflicting evidence and, given the enhancements and innovative approaches proposed here, it provides empirical evidence in support of a positive intertemporal risk-return tradeoff when examining several international stock markets.
The research questions this thesis addresses are as follow. Firstly, is it possible that extant conflicting evidence is manifested in the use of historical realized returns to proxy for investors’ forward-looking expected returns? Secondly, can accounting for shifts in investment opportunities (i.e. intertemporal risk) better explain investors’ risk aversion and changes in the dynamic risk premium? Thirdly, is it possible that conflicting findings are the result of neglecting to account for the possibility that there exist heterogeneous investors in the stock market with divergent expectations?
The empirical findings can be summarized as follows; firstly, there is a strong possibility that many existing studies cannot find a positive risk-return relation because they are relying on ex post historical realized returns as a proxy for investors’ forward-looking expected returns. Secondly, there is evidence in favor of the Merton (1973) notion that there exists intertemporal risk which impacts investors and that this type of risk should be considered. This has been also another reason why extant literature cannot agree on the nature of the intertemporal risk-return tradeoff. Finally, even after accounting for investor heterogeneity, the findings provide support for the Merton (1973) theoretical Intertemporal Capital Asset Pricing Model. Namely, in contrast to existing studies on the matter, there is evidence of fundamental traders over longer horizons and no evidence of feedback traders at such horizons. Although this sheds new light on some of the driving forces behind stock prices, the nature of investors’ degree of risk aversion seems to be best supported by the Merton (1973) theoretical Intertemporal Capital Asset Pricing Model.