Preference (economics) in the context of Preference map

The theory of consumer choice is the branch of microeconomics that relates preferences to consumption expenditures and to consumer demand curves. It analyzes how consumers maximize the desirability of their consumption (as measured by their preferences subject to limitations on their expenditures), by maximizing utility subject to a consumer budget constraint.Factors influencing consumers' evaluation of the utility of goods include: income level, cultural factors, product information and physio-psychological factors.

Consumption is separated from production, logically, because two different economic agents are involved. In the first case, consumption is determined by the individual. Their specific tastes or preferences determine the amount of utility they derive from goods and services they consume. In the second case, a producer has different motives to the consumer in that they are focussed on the profit they make. This is explained further by producer theory. The models that make up consumer theory are used to represent prospectively observable demand patterns for an individual buyer on the hypothesis of constrained optimization. Prominent variables used to explain the rate at which the good is purchased (demanded) are the price per unit of that good, prices of related goods, and wealth of the consumer.

Revealed preference theory, pioneered by economist Paul Anthony Samuelson in 1938, is a method of analyzing choices made by individuals, mostly used for comparing the influence of policies on consumer behavior. Revealed preference models assume that the preferences of consumers can be revealed by their purchasing habits.

Revealed preference theory arose because existing theories of consumer demand were based on a diminishing marginal rate of substitution (MRS). This diminishing MRS relied on the assumption that consumers make consumption decisions to maximise their utility. While utility maximisation was not a controversial assumption, the underlying utility functions could not be measured with great certainty. Revealed preference theory was a means to reconcile demand theory by defining utility functions by observing behaviour.

The labor theory of value (LTV) is a theory of value that argues that the exchange value of a good or service is determined by the total amount of "socially necessary labor" required to produce it. The contrasting system is typically known as the subjective theory of value.

The LTV is usually associated with Marxian economics, although it originally appeared in the theories of earlier classical economists such as Adam Smith and David Ricardo, and later in anarchist economics. Smith saw the price of a commodity as a reflection of how much labor it can "save" the purchaser. The LTV is central to Marxist theory, which holds that capitalists' expropriation of the surplus value produced by the working class is exploitative. Modern mainstream economics rejects the LTV and uses a theory of value based on subjective preferences.

In decision theory, the von Neumann–Morgenstern (VNM) utility theorem demonstrates that rational choice under uncertainty involves making decisions that take the form of maximizing the expected value of some cardinal utility function. The theorem forms the foundation of expected utility theory.

In 1947, John von Neumann and Oskar Morgenstern proved that any individual whose preferences satisfied four axioms has a utility function, where such an individual's preferences can be represented on an interval scale and the individual will always prefer actions that maximize expected utility. That is, they proved that an agent is (VNM-)rational if and only if there exists a real-valued function u defined by possible outcomes such that every preference of the agent is characterized by maximizing the expected value of u, which can then be defined as the agent's VNM-utility (it is unique up to affine transformations i.e. adding a constant and multiplying by a positive scalar). No claim is made that the agent has a "conscious desire" to maximize u, only that u exists.

Consumer behaviour is the study of individuals, groups, or organisations and all activities associated with the purchase, use and disposal of goods and services. It encompasses how the consumer's emotions, attitudes, and preferences affect buying behaviour, and how external cues—such as visual prompts, auditory signals, or tactile (haptic) feedback—can shape those responses. Consumer behaviour emerged in the 1940–1950s as a distinct sub-discipline of marketing, but has become an interdisciplinary social science that blends elements from psychology, sociology, social anthropology, anthropology, ethnography, ethnology, marketing, and economics (especially behavioural economics).

The study of consumer behaviour formally investigates individual qualities such as demographics, personality lifestyles, and behavioural variables (like usage rates, usage occasion, loyalty, brand advocacy, and willingness to provide referrals), in an attempt to understand people's wants and consumption patterns. Consumer behaviour also investigates on the influences on the consumer, from social groups such as family, friends, sports, and reference groups, to society in general (brand-influencers, opinion leaders).

In microeconomics, the expenditure function represents the minimum amount of expenditure needed to achieve a given level of utility, given a utility function and the prices of goods.

Formally, if there is a utility function ${\displaystyle u}$ that describes preferences over n goods, the expenditure function ${\displaystyle e(p,u^{*})}$ is defined as:

Utility maximization was first developed by utilitarian philosophers Jeremy Bentham and John Stuart Mill. In microeconomics, the utility maximization problem is the problem consumers face: "How should I spend my money in order to maximize my utility?" It is a type of optimal decision problem. It consists of choosing how much of each available good or service to consume, taking into account a constraint on total spending (income), the prices of the goods and their preferences.

Utility maximization is an important concept in consumer theory as it shows how consumers decide to allocate their income. Because consumers are modelled as being rational, they seek to extract the most benefit for themselves. However, due to bounded rationality and other biases, consumers sometimes pick bundles that do not necessarily maximize their utility. The utility maximization bundle of the consumer is also not set and can change over time depending on their individual preferences of goods, price changes and increases or decreases in income.

The term preference relation is used to refer to orderings that describe human preferences for one thing over an other.

• In mathematics, preferences may be modeled as a weak ordering or a semiorder, two different types of binary relation. One specific variation of weak ordering, a total preorder (= a connected, reflexive and transitive relation), is also sometimes called a preference relation.
• In computer science, machine learning algorithms are used to infer preferences, and the binary representation of the output of a preference learning algorithm is called a preference relation, regardless of whether it fits the weak ordering or semiorder mathematical models.
• Preference relations are also widely used in economics; see preference (economics).

In economics, an ordinal utility function is a function representing the preferences of an agent on an ordinal scale. Ordinal utility theory claims that it is only meaningful to ask which option is better than the other, but it is meaningless to ask how much better it is or how good it is. All of the theory of consumer decision-making under conditions of certainty can be, and typically is, expressed in terms of ordinal utility.

For example, suppose George tells us that "I prefer A to B and B to C". George's preferences can be represented by a function u such that: