理性思考與捷思法在決策結果之比較──預期效用法則與平均法則為例

Abstract

本研究旨在探討理性思考與捷思法在風險環境中，兩者決策結果之差異。本研究使用桌遊「金融戰略王」做為模擬真實投資市場之工具，模擬投資人在歷史循環模式市場與隨機漫步模式市場以預期效用法則與平均法則兩種分別代表理性思考與捷思法的決策策略進行連續五十年的投資行為，以時間序列分析確定整體投資績效之趨勢，並以單因子變異數分析比較十年、二十年、三十年、四十年與五十年投資績效之差異。結果顯示：在不同市場模式中，從50年長期趨勢來看，由預期效用理論衍生的效用法則，其產生的投資績效優於平均法則所產生的投資績效；另外，在不同的時間階段的比較中，效用法則的投資績效皆顯著高於平均法則。此結果表示在風險決策環境中，理性思考中的預期效用法則決策策略所產生之決策結果優於捷思法中的平均法則決策策略所產生之決策結果。最後研究者依據研究結果，建議在相關教學與研究中，應重視理性思考之認知歷程，並依研究限制給予後續研究相關建議。

The purpose of this study was to explore the difference of decision-making outcome between rational thinking and heuristics under a risk environment. Instrument of this study was the WALEX board game, as a simulator of the real world investment market. The decision-making strategies were the expected utility rule and the 1/n rule, representing the rational thinking and heuristics respectively. Both strategies were conducted for fifty years consecutively investment behavior in the historical cycle market model and the random walk market model. Time series analysis was conducted in order to ensure the trends of investment performance, and one-way ANOVA was used to examine the returns of investment in ten years, twenty years, thirty years, forty years, and fifty years. Results were as follows: From the 50-years trend perspective, the investment performance of expected utility rule was significantly higher than 1/n rule in both market models. In addition, the investment performance of expected utility rule was significantly higher than 1/n rule in the comparison of different time periods. The results indicated that under a risk environment, the expected utility rule of rational thinking decision-making strategy outperformed the 1/n rule of heuristics decision-making strategy. Based on this finding, the researcher suggested that the cognitive process of rational thinking should be emphasized in relevant teaching and studies. Finally, suggestions for future research were given according to the limitations of the study.