Fuzzy Decision-making Preferences In The Decision-making Scenario Dependent

Most people showed risk aversion, safety seeking when facing with safety option and risky option. In uncertain decision-making, when faced with the risky option and ambiguity option, most of them are also demonstrated ambiguity aversion and risk seeking. Camerer and Weber (1992) proposed conception of ambiguity medium, found that individuals are willing to pay a certain amount of ambiguity medium to seek further information, thus reducing the degree of ambiguity. Einhorn and Hogarth (1986) found that in the face of loss, ambiguity aversion will appear reversed. Heath (1991) found that the ambiguity aversion would not have happened when people have the ability or have sufficient knowledge to the sources of uncertainty. So under what conditions, it is ambiguity aversion, and under what conditions, it is ambiguity seeking? To address this issue, we discussed the problem from different opinion. The decision preference under different ambiguity degree, the decision preference when the ambiguity alternatives becoming the endowment of oneself, the effect on the decision preference whether decision-makers is a player or not, the decision preferences of the subjects in the different self-esteem levels. In addition, we also used a variety of different experimental task, choice task, betting task, bidding task and exchange task, respectively. The decision preferences were studied under different tasks. When the ambiguity aversion occurs, what the processing mechanism is? At present, there existed some ambiguity decision-making theories, mainly including variability theory, to meet peoples'needs, the heuristic theory. They simulate the mental process of the decision-making in different perspective. Which is more effective to explain the ambiguity aversion? Ambiguity decision-making is a special, complex risk decision-making or an independent decision-making type, which is a controversial issue in recent neuroeconomics, a series of fMRI studies reached a different opinion, respectively. But so far no one using event-related potentials technique, from the perspective of probability process, explores the relationship between ambiguity decision-making and risk decision-makingBased on the above issues and the existed debate, we have developed a research framework as a whole. An exploratory experiment was studied, the purpose to explore how subjects make the judgment and decision in the complete ambiguous scenarios (no relevant knowledge and experience). Single factor experiment within subjects was tested, the independent variable:the six different probability of decision-making. The dependent variable was the response time and the accuracy when made the decision. Experimental task is a task of judging winning or losing. The results showed that the participants made the decision using probabilistic thinking. Experiment 1 is to explore the decision-making preferences under different ambiguity degree. The purpose was to examine that the ambiguity aversion is stable or scenario-dependent. When the ambiguity degree changed, would the degree of ambiguity aversion and decision-making preference also change? In addition, this study further validate the theory of variability and anchoring adjustment heuristic theory, the bottle size effect and decision-making model was examined. Two factor experiment within subjects were tested, the independent variable 1 is the number of balls; the independent variables 2 is the degree of ambiguity, that is the possibility of pumping red ball from the bottle. The dependent variable 1 is the choice rate and the response time under the risky option and the ambiguity option. The dependent variable 2 is the assessment to the possibility of pumping the red ball from the bottle under the risky option and the ambiguity option. Experimental task was the variant of the Ellsberg paradox, using a forced-choice between two alternatives, so that subjects made a choice between the risky option and the ambiguity option. The results showed that:the different number of balls basically had no difference to the decision preferences, variability theory and heuristic adjustment theory has been only a part of the verification. The different ambiguity degree had influence on decision-making preferences; a higher degree of ambiguity, the subjects were inclined to dislike ambiguity, a lower degree of ambiguity; the subjects were inclined to ambiguity seeking. For a choice between two alternatives, decision-making process was more in line with the diffusion model. Experiment 2 was based on experiment 1, was an ERP research for different degree of ambiguity. According to the results of Experiment 1, we have chosen three different probability intervals. Experimental task was a variant of Ellsberg paradox, using a forced-choice between two alternatives, subjects made the choice between the ambiguity option and the risky option. The results showed that:there was no difference in the ERPs when processing the ambiguity of different degree. When processing the ambiguity alternative and the risky alternative, there was no difference in the ERPs in 0-100% and 50-50% conditions, as well as in the 20-80% and 50-50% conditions. The ERPs in 40-60% and 50-50% conditions was different. The difference wave is primarily a late positive component (LPC).These results show that from the perspective of the probability process (we represents the ambiguity degree of the alternative items by showing the probability of ambiguity interval in the experiment), the decision-making process of ambiguity decision-making and risk decision-making seems to be the same. The difference only existed in the decision process. When the difference between the two alternatives was large, decision-making was easy, and when he difference between the two alternatives was small, will produce a decision-making conflicts, and the decision-making was difficulty. Experiment 3 is a ERP study of risky decision-making under different predictive rate, through the above three experiments, we explored the way of thinking of the subjects' in the ambiguity scenarios, while explored the brain mechanisms of the ambiguity of different degree represented by the different probability interval.In the experiment 3, we made a ERP research on the different risk degree represented by different probabilities, comparing two studies aimed at further validation of the relationship between ambiguity decision and risk decision to determine whether the ambiguity decision-making is a special complex risk decision-making or not. The task is to make the judgment to the nine numbers, first of all, we give subjects a figure, soon give them a feedback figure, and subjects were asked to predict the feedback figure will be bigger or smaller than the figure provided in front.The number from one to nine was divided in to five categories according to the degree of uncertainty. Behavior results showed that the response time was increased with the strength of the uncertainty degree by contrasting the data of two conditions. The results showed that the mean correct percentage of the decision was accord with the percentage of prediction. The ERPs result indicated that both the uncertain decision and the certain decision elicited a later negative ERP component (N2) from 200 ms to 300 ms. There was a change in the mean amplitude among the five tasks and there was no difference between the probability of 50% and the probability of 62.5%. These results indicated the participants would make the representation of categorization when facing the uncertain decision and have the different perception to the different uncertainty degree. Experiment 4 is a research on endowment effect in ambiguous decision making. In this study, in the ambiguity medium and endowment effects perspective, we future discussed subjects' decision preference, when ambiguity alternative became into ones' own endowment. Two factors experimental design between subjects was taken. The first factor was the choice option; the second factor was the order for the bid, first WTP post WTA and first WTA post WTP. The experiment task was a variant of Ellsberg paradox. Subjects were required to complete three tasks:selection task, betting tasks, and pricing tasks. The results showed that:the ambiguity aversion effect have not found in the three tasks. This shows that the ambiguity aversion does not have stability. Subjects didn't show the endowment effect for the risky alternative and ambiguity alternative. Experiment 5 is a research on the endowment effect for the risky alternative and ambiguity alternative in different domains (gain and loss). People' attitudes towards ambiguity would change with the size of the income and the probability. When the profit value is positive, and the probability of gaining the profit value is also high, people will tend to risk decision-making at this time. But when faced with negative incomes, that is losses, and the probability of loss is also high, people will tend to ambiguity decision-making at this time. So it is necessary to study the ambiguity aversion, ambiguity medium and endowment effect from the perspective of gain and loss. The conclusions we drawed in the experiment 4 were inconsistent with the previous studies. The reason maybe that WTP gave a cap of price and WTA gave a floor to the price. The deviation of prices received is questionable. The decision-making is influential by this difference. In experiment 5, for which the problems in Experiment 4, by changing the guidance of language, the decision preference was further explored, which required subjects to give the price willing to pay and willingness to accept with choice tasks, pricing task and exchange tasks, in gain and lost domains. Three factors experimental design between subjects were tested. The independent variable 1:different scenarios. The independent variable 2:pricing conditions. The three independent variables:exchange conditions. The experimental task was a variant of Ellsberg paradox. The results showed that the subjects were risky preferences from the choice preferences, but win or lose scenario are influential to the choice preferences. There existed ambiguity aversion and ambiguity medium effect when subjects were asked to offer the price of "willing to pay" only in the winning WTP scenario. The subjects were ambiguity seeking when the ambiguous alternative is one's own endowment in losing scenarios as well as in winning scenarios. They thought they are more likely to make a return or reduce their losses in the ambiguity alternative. The impact of losing or winning scenario on the risky alternative should be more than on the ambiguity alternative. In the exchange condition, some subjects were ambiguity aversion, and are willing to pay ambiguity medium; but on the whole, they were not ambiguity aversion. And win or lose scenario had not much impact on the subjects'choice. The opinion that subjects were more inclined to ambiguity seeking in the loss has not been verified. There has been endowment effect for the ambiguity alternative. For the risky alternative, there was no endowment effect. There was no implicit ambiguity medium effect in this experiment. We explored the influence of the self-esteem on the decision-making preferences in the experiment 6. The two factors of mixed experimental design were adopted. The independent variable 1:self-esteem level was the between-subjects variable. The second independent variables: make decision for oneself and need to take responsibility for their own decision; make decision for their own companies and need to take responsibility for their own decision; make decision for their own companies and need not to take responsibility for their own decision; was the within-subjects variable. The dependent variable:the subjects' choice rate to the risky program (Program 1) and the ambiguity program (program 2 and program 3). The results showed that:the choice rate of three programs was basically the same for the subjects of the low self-esteem when they were decision-maker. They tend to ambiguity aversion when they are employee and need to take responsibility for the consequences of the decision-making. They tend to ambiguity seeking when they are employee and need not to take responsibility for the consequences of the decision-making. The subjects of the high self-esteem tend to risk seeking and ambiguity avoiding in these three conditions. Subjects of high self-esteem compared with the low self-esteem ones and medium self-esteem were more likely to ambiguity avoiding when need to bear the responsibility for the consequences of decision-making. Subjects of low self-esteem compared with the high self-esteem ones and medium self-esteem were more likely to ambiguity seeking when need not to bear the responsibility for the consequences of decision-making. The theory of defensive response that high self-esteem individuals were more defensive than individuals of low self-esteem was supported in this study.Integration of the above-mentioned experimental results, we draw the following conclusions: ambiguity aversion is not stable. Subjects'decision-making preferences are not the same in different scenarios, so the ambiguity decision-making preference is a scenario-dependent. From the perspective of the probability process, the decision-making process of ambiguity decision-making and risk decision-making seems to be the same. The difference only existed in the decision process. When the difference between the two alternatives was large, decision-making was easy, and when he difference between the two alternatives was small, will produce a decision-making conflicts, and the decision-making was difficulty.This demonstrated that the ambiguity decision-making seems to be a unique, complex risky decision-making.