Ambiguity aversion
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In decision theory and economics, ambiguity aversion (also known as uncertainty aversion) describes an attitude of preference for known risks over unknown risks. People would rather choose an option with fewer unknown elements than with many unknown elements. It is demonstrated in the Ellsberg paradox (i.e. that people prefer to bet on an urn with 50 red and 50 blue balls, than on one with 100 total balls but where the number of blue or red balls is unknown). There are a number of choices involving uncertainty and normally they can be classified in two categories: risky and ambiguous events. Risky events have a certain probability for a given outcome. Ambiguous events have a much greater degree of uncertainty. This includes the uncertainty of outcome and also the probability of an event occurring or the payoff associated with such events. The reaction is behavioral and still being formalized. Ambiguity aversion can be used to explain incomplete contracts, volatility in stock markets, and selective abstention in elections (Ghirardato & Marinacci, 2001)
Ambiguity aversion vs. risk aversion
The distinction between ambiguity aversion and risk aversion is important but subtle. Risk aversion comes from a situation where a probability can be assigned to each possible outcome of a situation. Ambiguity aversion applies to a situation when the probabilities of outcomes are unknown (Epstein 1999). The main idea behind ambiguity aversion encompasses the idea of risk aversion. A real world consequence of increased ambiguity aversion is the increased demand for insurance because the general public are averse to the unknown events that will affect their lives and property (Alary, Treich, and Gollier 2010).
Measurements of ambiguity aversion
Ambiguity aversion is a person’s rational attitude towards the probability of future outcomes, both unfavorable and favorable. People who are “ambiguity averse” will increase the probability of the unfavorable prospect. Ambiguity aversion has been widely observed in individuals judgments, especially when it comes to pairs of individuals. There are both risky and cautious shifts that can take place between individuals’ original judgements and current judgments and ambiguity aversion investigates those reasons.