This paper presents an experiment on risk taking and evaluation periods. The study tests whether the period over which individuals evaluate outcomes influences their investment in risky assets. The results show that the more frequently returns are evaluated, the more risk-averse investors will be. These findings support the behavioral hypothesis of 'myopic loss aversion,' which suggests that people are more sensitive to losses than to gains. The results have relevance for the equity premium puzzle and marketing strategies of fund managers. The experiment involved two groups of participants. The first group (high frequency) received feedback after each round and could adjust their choices. The second group (low frequency) received feedback only after three rounds and could only adjust their choices after three rounds. The study found that subjects in the low frequency group made more risky choices, supporting the hypothesis that evaluating outcomes over a longer period makes risky options more attractive. The design of the experiment aimed to manipulate the evaluation period of subjects. The results showed that subjects in the low frequency group bet more in the risky lottery, indicating that they were more willing to take risks when they evaluated outcomes in a more aggregated way. The findings support the explanation of the equity premium puzzle proposed by Benartzi and Thaler, suggesting that the size of the equity premium is consistent with investors evaluating their portfolios annually and weighing losses about 2.5 times as large as gains. The study also highlights the importance of controlled experiments in testing behavioral hypotheses. While the evidence presented by Benartzi and Thaler is circumstantial, the experimental results provide direct support for the presence of myopic loss aversion. The results suggest that manipulating the evaluation period can influence risk-taking behavior, with implications for both theoretical and practical applications in finance and marketing.This paper presents an experiment on risk taking and evaluation periods. The study tests whether the period over which individuals evaluate outcomes influences their investment in risky assets. The results show that the more frequently returns are evaluated, the more risk-averse investors will be. These findings support the behavioral hypothesis of 'myopic loss aversion,' which suggests that people are more sensitive to losses than to gains. The results have relevance for the equity premium puzzle and marketing strategies of fund managers. The experiment involved two groups of participants. The first group (high frequency) received feedback after each round and could adjust their choices. The second group (low frequency) received feedback only after three rounds and could only adjust their choices after three rounds. The study found that subjects in the low frequency group made more risky choices, supporting the hypothesis that evaluating outcomes over a longer period makes risky options more attractive. The design of the experiment aimed to manipulate the evaluation period of subjects. The results showed that subjects in the low frequency group bet more in the risky lottery, indicating that they were more willing to take risks when they evaluated outcomes in a more aggregated way. The findings support the explanation of the equity premium puzzle proposed by Benartzi and Thaler, suggesting that the size of the equity premium is consistent with investors evaluating their portfolios annually and weighing losses about 2.5 times as large as gains. The study also highlights the importance of controlled experiments in testing behavioral hypotheses. While the evidence presented by Benartzi and Thaler is circumstantial, the experimental results provide direct support for the presence of myopic loss aversion. The results suggest that manipulating the evaluation period can influence risk-taking behavior, with implications for both theoretical and practical applications in finance and marketing.