In
economics and other
social sciences,
preference refers to the set of assumptions related to ordering some alternatives, based on the degree of
happiness, satisfaction,
gratification, morality, enjoyment, or
utility they provide. The concept of preferences is used in post-
World War II neoclassical economics to provide observable evidence in relation to people's actions. These actions can be described by
Rational Choice Theory, where individuals make decisions based on rational preferences which are aligned with their self-interests in order to achieve an optimal outcome. Consumer preference, or consumers' preference for particular brands over identical products and services, is an important notion in the psychological influence of consumption. Consumer preferences have three properties: completeness, transitivity and non-satiation. For a preference to be rational, it must satisfy the axioms of
transitivity and
Completeness (statistics). The first axiom of transitivity refers to consistency between preferences, such that if x is preferred to y and y is preferred to z, then x has to be preferred to z. The second axiom of completeness describes that a relationship must exist between two options, such that x must be preferred to y or y must be preferred to x, or is indifferent between them. If preferences are both transitive and complete, the relationship between preference can be described by a
utility function. This is because the axioms allow for preferences to be ordered into one equivalent ordering with no preference cycles. Maximising utility does not imply maximise happiness, rather it is an optimisation of the available options based on an individual's preferences. The so-called
Expected Utility Theory (EUT), which was introduced by
John von Neumann and
Oskar Morgenstern in 1944, explains that so long as an agent's preferences over risky options follow a set of
axioms, then he is maximizing the expected value of a utility function. In utility theory, preference relates to decision makers' attitudes towards rewards and hazards. The specific varieties are classified into three categories: 1) risk-averse, that is, equal gains and losses, with investors participating when the loss probability is less than 50%; 2) the risk-taking kind, which is the polar opposite of type 1); 3) Relatively risk-neutral, in the sense that the introduction of risk has no clear association with the decision maker's choice. The mathematical foundations of most common types of preferences — that are representable by quadratic or additive functions — laid down by
Gérard Debreu Empirical evidence has shown that the usage of rational preferences (and
Rational Choice Theory) does not always accurately predict human behaviour because it makes unrealistic assumptions. In response to this,
neoclassical economists argue that it provides a normative model for people to adjust and optimise their actions.
Behavioural economics describes an alternative approach to predicting human behaviour by using psychological theory which explores deviations from rational preferences and the standard economic model. It also recognises that rational preferences and choices are limited by
heuristics and
biases.
Heuristics are rules of thumb such as elimination by aspects which are used to make decisions rather than maximising the
utility function. Economic
biases such as reference points and
loss aversion also violate the assumption of rational preferences by causing individuals to act irrationally. Individual preferences can be represented as an
indifference curve given the underlying assumptions. Indifference curves graphically depict all product combinations that yield the same amount of usefulness. Indifference curves allow us to graphically define and rank all possible combinations of two commodities. The graph's three main points are: • If more is better, the indifference curve dips downward. • Greater transitivity indicates that the indifference curves do not overlap. • A propensity for diversity causes indifference curves to curve inward. == Risk preference ==