Theories of Risk: Testing Investor Behaviour on the Taiwan Stock and Stock Index Futures Markets

Abstract

Investor behavior towards risk lies at the heart of economic decision making in general and modern investment theory and practice in particular. This paper uses both the mean-variance (MV) criterion and stochastic dominance (SD) procedures to analyze the preferences for four of the most widely studied investor types in the Taiwan stock and stock index futures market. We find that risk averters (concave utility function) prefer spot to futures, whereas risk seekers (convex utility function) prefer futures to spot. Our findings also show that investors with S-shaped utility functions prefer spot (futures) to futures (spot) when markets move upward (downward). Finally, our results imply that investors with reverse S-shaped utility functions prefer futures (spot) to spot (futures) when markets move upward (downward). These results are robust with respect to sub-periods, spot returns including dividends and diversification. Although we do not check whether risk averters, risk seekers, and investors with S-shaped and reverse Sshaped utility functions actually exist in the market, we do show that their existence is plausible. The implications of our findings on market efficiency and the existence of arbitrage opportunities are also discussed in this study.

Keywords: stochastic dominance; risk aversion; risk seeking; prospect theory; behavioral economics; stock index futures

JEL Classification: C14; G12; G15