Exploring the challenge to the divided self of economics, ‘Homo Economicus’.
- Understand why the mainstream economic assumption of ‘rational humans’ is criticized.
- Learn about the core theories of behavioral economics (prospect theory, nudging, etc.) through concrete examples.
- Identify the impact of the conflict and integration of the two economics on our lives and policies.
I. The Two Faces of Economics: Rational Humans vs. Actual Humans
20th-century mainstream economics assumed ‘Homo Economicus’, an ideal human who maximizes their utility based on economic rationality. This ’economic man’ processes all information and makes optimal choices based on perfect rationality and self-interest.
Of course, this is far from reality. However, this assumption was a ‘methodological necessity’ for modeling complex economic phenomena mathematically and establishing predictable theories. Thanks to this, powerful analytical tools such as the laws of supply and demand and market equilibrium theory could develop. Behavioral economics brings the ‘human’ of reality back to the center of economics, which had been sacrificed for theoretical elegance.
Events like the 2008 global financial crisis shook the belief in rational markets. As anomalies, such as market bubbles and crashes, repeatedly occurred that could not be explained by rational theories alone, the call to include psychological factors in economic analysis grew louder.
This is where Behavioral Economics emerged. It explores how ‘actual humans (Homo Sapiens)’, influenced by emotions and biases, make decisions by borrowing insights from psychology and cognitive science.
II. The Dawn of Behavioral Economics: The Discovery of ‘Bounded Rationality’
The intellectual roots of behavioral economics trace back to 1978 Nobel laureate Herbert A. Simon. He explored human decision-making from a realistic perspective across various disciplines.
Simon’s key contribution is the concept of ‘Bounded Rationality’. He argued that due to limitations in cognitive abilities and information search, humans follow the principle of ‘satisficing’, finding ‘good enough’ alternatives that meet minimal criteria instead of seeking the ‘optimal solution’.
This was revolutionary in revealing that human irrationality stems not from fickle emotions but from a systematic phenomenon arising from the mismatch between ‘problem complexity’ and ’the finite processing capacity of the brain’. This opened a new field of research into ‘predictable irrationality’.
III. Why Do Humans Make Irrational Choices?
Building on Simon’s foundation, psychologists Daniel Kahneman and Amos Tversky demonstrated through experiments that human irrationality is a predictable pattern, or ‘systematic bias’.
3.1. Prospect Theory: A New Standard for Value Judgment
Prospect Theory is the most fundamental theory of behavioral economics.
- Reference Point: People evaluate value subjectively based on ‘gains’ and ’losses’ relative to their current state, rather than the absolute amount of final assets.
- Loss Aversion: People feel the pain of losses about 2 to 2.5 times more intensely than the pleasure of gains. This explains why we are sensitive to losses and prefer to maintain the status quo.
- S-shaped Value Function: Value judgments follow an asymmetric ‘S-shaped’ curve, becoming less sensitive to changes as the size of gains and losses increases.
Table 1: Comparison of Key Assumptions of Expected Utility Theory and Prospect Theory
| Feature | Expected Utility Theory | Prospect Theory |
|---|---|---|
| Basis for Value Evaluation | Absolute level of final assets | Gains/Losses from the reference point |
| Attitude Towards Risk | Consistent risk aversion | Risk-averse in gains, risk-seeking in losses |
| Value Function | Concave function | Asymmetric S-shaped function based on reference point |
| Sensitivity to Losses and Gains | Symmetric | About 2 to 2.5 times more sensitive to losses (loss aversion) |
| Probability Processing | Linearly weights objective probabilities | Overestimates low probabilities, underestimates high probabilities |
3.2. Framing Effect: The Frame of the Problem Determines Choice
The ‘Framing Effect’ is the phenomenon where choices vary depending on how the same problem is presented. The ‘Asian disease problem’ experiment is a representative example.
- Positive Frame (‘Saves 200 people’): 72% choose a certain alternative (risk-averse)
- Negative Frame (‘400 people die’): 78% choose an uncertain alternative (risk-seeking)
The outcomes are mathematically identical, but preferences completely reversed based on the frame of ‘saves (gain)’ and ‘dies (loss)’. This provides strong evidence that human choices are significantly influenced by psychological reference points rather than rational calculations.
3.3. Anchoring Effect and Heuristics
The ‘Anchoring Effect’ is a bias where the first piece of information serves as an ‘anchor’ that distorts subsequent judgments. An experiment showed that an unrelated number from a spinning wheel influenced estimates of the proportion of African countries among UN member states.
This effect demonstrates that humans rely on mental shortcuts, or ‘heuristics’, instead of logic when solving complex problems.
3.4. Endowment Effect: The Value of My Own is Different
The ‘Endowment Effect’ is the phenomenon of valuing owned items much higher than when not owned. I have also felt the temptation to price my items higher than market value when selling them in a second-hand market. This clearly shows how loss aversion manifests in reality.
In Richard Thaler’s ‘mug experiment’, students who owned the mug wanted to sell it for an average of $5.25, while those wanting to buy it offered $2.75. The value nearly doubled simply because it became ‘mine’. Selling the mug is perceived as a ’loss of ownership’.
Table 2: Summary of Major Behavioral Biases
| Bias | Definition | Canonical Experiment | Real-World Example |
|---|---|---|---|
| Framing Effect | The phenomenon where judgments and choices vary based on the presented frame | Asian disease problem | ‘10% fat’ vs ‘90% lean meat’, 90% success rate vs 10% mortality rate |
| Anchoring Effect | The phenomenon where initial information serves as a reference point affecting subsequent judgments | Spinning wheel and estimating the number of African countries | Initial offer price in negotiations, displaying ‘regular price’ and ‘discount price’ in stores |
| Endowment Effect | The phenomenon of valuing owned items higher | Mug experiment | Pricing one’s own car higher when selling, hesitating to sell stocks |
| Status Quo Bias | The tendency to maintain the current state without a special reason | Default options in pension plans | Delaying cancellation of subscription services, habitually going to the same restaurant |
| Mental Accounting | The phenomenon of assigning different values based on the source or use of money | Lost cash vs lost movie ticket | Spending ‘windfall’ easily while saving salary, conservative management of retirement funds |
IV. Financial Markets: The Clash of the Efficiency Myth and Behavioral Finance
The fiercest battleground between rationalism and behavioralism is the financial markets. The mainstream economic ‘Efficient Market Hypothesis (EMH)’ claims that asset prices reflect all available information immediately and completely. According to this theory, no one can consistently exceed the market average return.
However, phenomena like the dot-com bubble and financial crises are difficult to explain with EMH. Behavioral finance scholars like Robert Shiller have demonstrated ’excess volatility’, where actual stock price fluctuations cannot be explained solely by changes in intrinsic value.
Behavioral finance explains that investors’ overconfidence bias, herd behavior, and representativeness heuristic create ‘irrational exuberance’ that forms bubbles.
The joint awarding of the 2013 Nobel Prize in Economics to Eugene Fama, the founder of EMH, and Robert Shiller, its critic, is symbolic. It suggests that while markets may be efficient in the short term (Fama), they are vulnerable to massive bubbles and collapses driven by investor sentiment in the long term (Shiller).
V. Sharp Criticisms of Behavioral Economics
While behavioral economics has achieved great success, it faces several criticisms.
- Fragmentation of Theory: It is merely a list of numerous biases, lacking a unified theory that encompasses them. It is difficult to predict in which situations which biases will appear.
- Limitations of Predictive Power: It excels at ’explaining’ past behavior but is criticized for lacking the ability to quantitatively ‘predict’ the future.
- Limitations of Laboratory Studies: Questions arise about the ’external validity’ of whether controlled laboratory results will manifest similarly in complex real-world markets.
- Role of Learning and Markets: There are counterarguments that individuals learn from mistakes and that markets can eliminate irrational actors, allowing them to operate rationally in the long run.
VI. The Soft Power That Changes the World: The Light and Dark of ‘Nudge’
Insights from behavioral economics have significantly influenced real-world policies through the ‘Nudge’ theory. Nudging is an approach that gently guides people to make better decisions by changing the design of choices without coercion or prohibition.
- Policy Examples: Changing retirement plan enrollment to ‘opt-out (default enrollment)’ to increase savings rates or including the phrase “90% of your neighbors have already paid their taxes” on tax bills to increase compliance rates are representative examples.
- Ethical Debate: Nudging raises debates between the ’libertarian’ aspect that respects freedom of choice and the ‘paternalistic interventionism’ aspect where the state intervenes for individuals’ better lives. Critics worry that nudging could become a subtle form of ‘manipulation’ that infringes on individual autonomy.
Ultimately, the debate surrounding nudging illustrates the fundamental dilemma between ‘individual autonomy’ and ’the welfare of the community’.
Conclusion
- Summary of Key Points
- Limits of Rationality: The ‘Homo Economicus’ of traditional economics differs from reality, and humans possess ‘bounded rationality’ under cognitive constraints.
- Predictable Irrationality: Behavioral economics has proven that human irrational behavior is systematic and predictable through prospect theory, framing effects, etc.
- From Conflict to Integration: Behavioral economics is not replacing mainstream economics but is moving towards an integrative direction that enhances the explanatory power of economics by adding psychological insights.
- Next Action Suggestion (CTA) What psychological biases were hidden in your consumption or investment decisions today? Explore the principles of behavioral economics in your daily life and consider making better choices.
References
- [Economics and the World] Homo Economicus Yeongnam Ilbo
- Economic Man Wikipedia
- Behavioral Economics | Norio Domono Kyobo Bookstore
- Homo Economicus, Hesitating Before Choices University Newspaper
- Philosophical Reflection on the Concept of Economic Rationality* Seoul National University Humanities Research Institute
- Behavioral Economics Namu Wiki
- The Human in Economics and Finance is Not Rational… Breaking the Framework of Traditional Economics Hankyung Sanggeul Sanggeul
- Prospect Theory Wikipedia
- Efficient Market Hypothesis Wikipedia
- The Ongoing Debate on the Efficient Market Hypothesis Through the Nobel Prize in Economics Heiri Fund Services
- Criticisms of Behavioral Economics Economics Online
- Nudge: Final Edition Aladin