Behavioral economics

Behavioral economics is the study of the psychological factors involved in the decisions of individuals or institutions, and how these decisions deviate from those implied by traditional economic theory.
Behavioral economics is primarily concerned with the bounds of rationality of economic agents. Behavioral models typically integrate insights from psychology, neuroscience and microeconomic theory.
Behavioral economics began as a distinct field of study in the 1970s and 1980s, but can be traced back to 18th-century economists, such as Adam Smith, who deliberated how the economic behavior of individuals could be influenced by their desires.
The status of behavioral economics as a subfield of economics is a fairly recent development; the breakthroughs that laid the foundation for it were published through the last three decades of the 20th century. Behavioral economics is still growing as a field, being used increasingly in research and in teaching.

History

Early classical economists included psychological reasoning in much of their writing, though psychology at the time was not a recognized field of study. In The Theory of Moral Sentiments, Adam Smith wrote on concepts later popularized by modern Behavioral Economic theory, such as loss aversion. Jeremy Bentham, a Utilitarian philosopher in the 1700s conceptualized utility as a product of psychology. Other economists who incorporated psychological explanations in their works included Francis Edgeworth, Vilfredo Pareto and Irving Fisher.
A rejection and elimination of psychology from economics in the early 1900s brought on a period defined by a reliance on empiricism. There was a lack of confidence in hedonic theories, which saw pursuance of maximum benefit as an essential aspect in understanding human economic behavior. Hedonic analysis had shown little success in predicting human behavior, leading many to question its viability as a reliable source for prediction.
There was also a fear among economists that the involvement of psychology in shaping economic models was inordinate and a departure from accepted principles. They feared that an increased emphasis on psychology would undermine the mathematic components of the field.
To boost the ability of economics to predict accurately, economists started looking to tangible phenomena rather than theories based on human psychology. Psychology was seen as unreliable to many of these economists as it was a new field, not regarded as sufficiently scientific. Though a number of scholars expressed concern towards the positivism within economics, models of study dependent on psychological insights became rare. Economists instead conceptualized humans as purely rational and self-interested decision makers, illustrated in the concept of homo economicus.
A pivotal early challenge to the dominance of expected-utility theory was mounted by French economist Maurice Allais. In his seminal 1953 paper, Allais presented empirical examples now known as the Allais paradox — notably the “common-ratio” and “common-consequence” effects — which demonstrated systematic deviations from expected-utility maximization. Experimental evidence summarized in recent meta-analytic work confirms that the common-ratio effect remains observable under many conditions. For instance, Blavatskyy, Panchenko & Ortmann re-examined data from 39 prior experiments and found that about 59.4% of designs reproduced the common-ratio pattern.
The resurgence of psychology within economics, which facilitated the expansion of behavioral economics, has been linked to the cognitive revolution. In the 1960s, cognitive psychology began to shed more light on the brain as an information processing device. Psychologists in this field, such as Ward Edwards, Amos Tversky and Daniel Kahneman began to compare their cognitive models of decision-making under risk and uncertainty to economic models of rational behavior. These developments spurred economists to reconsider how psychology could be applied to economic models and theories. Concurrently, the Expected utility hypothesis and discounted utility models began to gain acceptance. In challenging the accuracy of generic utility, these concepts established a practice foundational in behavioral economics: Building on standard models by applying psychological knowledge.
Mathematical psychology reflects a long-standing interest in preference transitivity and the measurement of utility.

Development of behavioral economics

In 2017, Niels Geiger, a lecturer in economics at the University of Hohenheim conducted an investigation into the proliferation of behavioral economics. Geiger's research looked at studies that had quantified the frequency of references to terms specific to behavioral economics, and how often influential papers in behavioral economics were cited in journals on economics. The quantitative study found that there was a significant spread in behavioral economics after Kahneman and Tversky's work in the 1990s and into the 2000s.

	1979 paper	1992 paper	1974 paper	1981 paper	1986 paper
1974-78	0	0	1	0	0
1979-83	1	0	4	3	0
1984-88	7	0	0	1	0
1989-93	19	1	2	6	3
1993-98	37	16	12	7	6
1999-2003	51	20	5	15	11
2004-08	80	48	18	15	16
2009-13	161	110	59	38	19
Total Citations	356	195	101	85	55

Bounded rationality

is the idea that when individuals make decisions, their rationality is limited by the tractability of the decision problem, their cognitive limitations and the time available.
Herbert A. Simon proposed bounded rationality as an alternative basis for the mathematical modeling of decision-making. It complements "rationality as optimization", which views decision-making as a fully rational process of finding an optimal choice given the information available. Simon used the analogy of a pair of scissors, where one blade represents human cognitive limitations and the other the "structures of the environment", illustrating how minds compensate for limited resources by exploiting known structural regularity in the environment. Bounded rationality implicates the idea that humans take shortcuts that may lead to suboptimal decision-making. Behavioral economists engage in mapping the decision shortcuts that agents use in order to help increase the effectiveness of human decision-making. Bounded rationality finds that actors do not assess all available options appropriately, in order to save on search and deliberation costs. As such decisions are not always made in the sense of greatest self-reward as limited information is available. Instead agents shall choose to settle for an acceptable solution. One approach, adopted by Richard M. Cyert and James G. March in their 1963 book A Behavioral Theory of the Firm, was to view firms as coalitions of groups whose targets were based on satisficing rather than optimizing behaviour. Another treatment of this idea comes from Cass Sunstein and Richard Thaler's Nudge. Sunstein and Thaler recommend that choice architectures are modified in light of human agents' bounded rationality. A widely cited proposal from Sunstein and Thaler urges that healthier food be placed at sight level in order to increase the likelihood that a person will opt for that choice instead of less healthy option. Some critics of Nudge have lodged attacks that modifying choice architectures will lead to people becoming worse decision-makers.

Prospect theory

In 1979, Kahneman and Tversky published Prospect Theory: An Analysis of Decision Under Risk, that used cognitive psychology to explain various divergences of economic decision making from neo-classical theory. Kahneman and Tversky utilising prospect theory determined three generalisations; gains are treated differently than losses, outcomes received with certainty are overweighed relative to uncertain outcomes and the structure of the problem may affect choices. These arguments were supported in part by altering a survey question so that it was no longer a case of achieving gains but averting losses and the majority of respondents altered their answers accordingly. In essence proving that emotions such as fear of loss, or greed can alter decisions, indicating the presence of an irrational decision-making process. Prospect theory has two stages: an editing stage and an evaluation stage. In the editing stage, risky situations are simplified using various heuristics. In the evaluation phase, risky alternatives are evaluated using various psychological principles that include:

Reference dependence: When evaluating outcomes, the decision maker considers a "reference level". Outcomes are then compared to the reference point and classified as "gains" if greater than the reference point and "losses" if less than the reference point.
Loss aversion: Losses are avoided more than equivalent gains are sought. In their 1992 paper, Kahneman and Tversky found the median coefficient of loss aversion to be about 2.25, i.e., losses hurt about 2.25 times more than equivalent gains reward.
Non-linear probability weighting: Decision makers overweigh small probabilities and underweigh large probabilities—this gives rise to the inverse-S shaped "probability weighting function".
Diminishing sensitivity to gains and losses: As the size of the gains and losses relative to the reference point increase in absolute value, the marginal effect on the decision maker's utility or satisfaction falls.

In 1992, in the Journal of Risk and Uncertainty, Kahneman and Tversky gave a revised account of prospect theory that they called cumulative prospect theory. The new theory eliminated the editing phase in prospect theory and focused just on the evaluation phase. Its main feature was that it allowed for non-linear probability weighting in a cumulative manner, which was originally suggested in John Quiggin's rank-dependent utility theory. Psychological traits such as overconfidence, projection bias and the effects of limited attention are now part of the theory. Other developments include a conference at the University of Chicago, a special behavioral economics edition of the Quarterly Journal of Economics, and Kahneman's 2002 Nobel Prize for having "integrated insights from psychological research into economic science, especially concerning human judgment and decision-making under uncertainty."
A further argument of Behavioural Economics relates to the impact of the individual's cognitive limitations as a factor in limiting the rationality of people's decisions. Sloan first argued this in his paper 'Bounded Rationality' where he stated that our cognitive limitations are somewhat the consequence of our limited ability to foresee the future, hampering the rationality of decision. Daniel Kahneman further expanded upon the effect cognitive ability and processes have on decision making in his book Thinking, Fast and Slow. He delved into two forms of thought: fast thinking, which he considered "operates automatically and quickly, with little or no effort and no sense of voluntary control", and slow thinking, the allocation of cognitive ability, choice, and concentration. Fast thinking utilises heuristics, or shortcuts, which provide an immediate but often irrational and imperfect solution. He proposed that hindsight bias, confirmation bias, and outcome bias originate from such shortcuts. A key example of fast thinking and the resultant irrational decisions is the 2008 financial crisis.