Yesterday I
suggested that when there is a state with a very tiny probability occurs, many
people are betting against the existence of the state; therefore, when the
state becomes the reality, it causes greater impacts than the difference of the
expected outcome and the state outcome. Today I want to further discuss this
topic.
The expected outcome
is the accumulation of the products of each state's probability and its
outcome. However, when it comes to individual decisions, in some cases,
individuals have to make their choices between several states and the expected
outcomes are not guaranteed. Each individual has his/her personal risk
preference and based on their risk preferences, they choose their preferred
states. It is commonly believed that the majority of the population has risk
averse risk preferences. If I assume that all individuals in the population
have risk averse risk preferences, when a state has a higher probability, the
number of people choosing this state becomes larger. When more people choose
one particular state, the price for this state rises as the demand increases,
so the return for the state decreases. Vice verse, the returns for states with
lower probabilities become larger.
In addition, if
assuming it is a zero-sum game, the overall outcome does not change, so the
average return does not change and is meaningless. The median outcome or return
in the population changes when we assume risk averse risk preferences or risk
neutral risk preference, as the number of people choosing states with high
probabilities under the risk averse risk preference assumption is greater than
the number under the risk neutral risk preference assumption, the returns for
states with high probabilities under the risk averse risk preference assumption
are lower than the returns for the same states under the risk neutral risk
preference assumption. Therefore, the median return of individuals when the
general risk preference of the population is risk averse is lower than the
median return and the expected return of individuals when the general risk
preference of the population is risk neutral.
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