IBV · Fachoberschule Bayern · Grade 11 · Learning Area 4 · valid from school year 2026/27
approx. 12 lessonsbilingualbehavioural economicsbiasesnudging
All content on this page follows the official LehrplanPLUS Bayern.
Understanding and optimising decisions from a behavioural economics perspective
Classical economic models often assume that people make rational decisions. Real people, however, do not always behave like perfectly calculating decision-makers. Behavioural economics investigates these systematic deviations. In this learning area, students first experience decision-making in experiments, then explain recurring behavioural patterns and finally analyse how companies and policymakers can use behavioural insights – including the ethical limits of nudging.
Contents
- From homo economicus to behavioural economics
- Why experiments?
- Ultimatum game
- What is a bias?
- Sunk-cost bias
- Hyperbolic discounting
- Anchoring
- Nudging
- Environmental policy
- Public health
- Marketing
- Ethics of nudging
- UNTERNEHMER AG
- Exam & transfer tasks
1. From homo economicus to behavioural economics
In the model of the homo economicus, economic actors are assumed to process relevant information rationally and choose the alternative that best serves their objectives. This assumption is useful for many models – for example the perfectly competitive market from Learning Area 3. Behavioural economics does not simply declare classical economics “wrong”. It adds evidence about how people actually make decisions under limited attention, time pressure, uncertainty, emotions and social influences.
| Classical model | Behavioural perspective |
|---|---|
| consistent preferences | preferences and choices can depend on context |
| rational evaluation of alternatives | heuristics and biases can systematically influence evaluation |
| past, irrecoverable costs should not affect a current decision | people may nevertheless continue because of sunk costs |
| future consequences are discounted consistently | people may strongly favour immediate rewards |
| irrelevant starting values should not matter | anchors can influence estimates and choices |
2. Why does the curriculum start with experiments?
The official competence expectation is deliberately action-oriented: students should experience how people systematically deviate from the rational model. A small experiment makes the conflict between theoretical prediction and actual behaviour visible before terminology is introduced.
3. The ultimatum game: money versus fairness
The ultimatum game is an example explicitly named in LehrplanPLUS. Two people must divide a fixed amount. The proposer suggests a split. The responder can accept or reject it. If the responder accepts, the money is divided as proposed. If the responder rejects, both receive nothing.
A narrowly self-interested rational benchmark predicts that the responder should accept any positive amount because a small positive payoff is financially better than zero. In real experiments, behaviour can differ because fairness, reciprocity and social norms matter. The important lesson is not that people are “irrational” in every situation, but that the simple benchmark may omit motives that influence real decisions.
4. Biases: systematic patterns in judgement and choice
A cognitive bias is a systematic tendency that can influence judgement or choice. LehrplanPLUS requires three examples in particular: sunk costs, hyperbolic discounting and anchoring.
5. Sunk-cost bias: “We have already invested so much…”
Sunk costs are costs that have already been incurred and cannot be recovered. A rational forward-looking decision should compare only the future consequences of the available alternatives. Nevertheless, people and organisations may continue an unfavourable project because they have already invested money, time or effort.
| Wrong decision frame | Relevant decision frame today |
|---|---|
| “If we stop, the €180,000 was wasted.” | The €180,000 is irrecoverable under both alternatives. |
| Continue: “protect” past investment | Compare future €120,000 with future €80,000 and all future benefits/risks. |
6. Hyperbolic discounting: why “now” can dominate “later”
People often value an immediate reward disproportionately strongly compared with a delayed reward. This can create time-inconsistent preferences: a person may prefer a larger later benefit when both alternatives are far away, but switch to the smaller immediate benefit when “now” arrives.
Choice B: €50 in twelve months or €60 in thirteen months?
The time gap is one month in both cases. If preferences change mainly because one option becomes immediate, this illustrates present bias and hyperbolic discounting.
7. Anchoring: when a starting value pulls our judgement
An anchor is an initial value or reference point that can influence a later estimate or decision – even when the anchor contains little useful information.
8. Nudging: changing choice architecture
A nudge changes the way choices are presented or structured without simply removing alternatives. The aim is to influence behaviour through the choice architecture. Examples can include defaults, reminders, ordering, salience or feedback.
9. Nudging in environmental policy
10. Nudging in public health
LehrplanPLUS explicitly names public health as an application area. A cafeteria may place healthier choices at eye level while other products remain available. The behavioural mechanism is not a prohibition but increased salience and easier access.
11. Behavioural economics in marketing
Marketing frequently shapes the decision environment. Anchors, defaults, product order, scarcity cues and framing can affect choices. The relevant competence is not merely to identify a technique, but to analyse its mechanism and discuss its consequences from different perspectives.
| Measure | Possible behavioural mechanism | Question for evaluation |
|---|---|---|
| reference price | anchoring | Is the reference informative and transparent? |
| preselected option | default / inertia | Can customers change it easily? |
| prominent placement | salience | Does it help orientation or manipulate attention? |
| “today only” message | focus on immediate consequence | Is the scarcity genuine and clearly communicated? |
12. The ethics of nudging
The official curriculum requires students to discuss the ethical justifiability of nudging. A good judgement therefore needs criteria rather than a simple “good/bad” label.
| Criterion | Questions |
|---|---|
| Transparency | Can affected people understand that the decision environment has been deliberately designed? |
| Autonomy | Are meaningful alternatives preserved and easy to choose? |
| Purpose | Does the measure primarily benefit the decision-maker, society, the company, or another actor? |
| Evidence | Is there a plausible behavioural mechanism and evidence that the intervention works? |
| Proportionality | Is the intervention mild relative to the objective pursued? |
| Distribution | Are some groups affected differently or disadvantaged? |
13. Integrated case: UNTERNEHMER AG
The management team is deciding whether to stop an unsuccessful development project. At the same time, the sales department is redesigning an online shop and the sustainability team wants employees to reduce energy use.
14. Exam and transfer training
15. Typical mistakes
| Mistake | Better reasoning |
|---|---|
| “Behavioural economics proves people are irrational.” | It studies systematic deviations from specific rational-model predictions and additional motives. |
| Every mistake is called a bias. | A bias is a systematic tendency, not a random error. |
| Past expenditure is added to future alternatives. | Irrecoverable sunk costs are separated from future decision-relevant consequences. |
| Hyperbolic discounting means “future benefits are worthless”. | The key issue is disproportionate weighting of immediacy and possible preference reversals. |
| Any number is automatically an anchor. | Explain how an initial/reference value influences subsequent judgement. |
| Every incentive is a nudge. | Analyse whether the intervention mainly changes choice architecture rather than imposing a major financial incentive, penalty or prohibition. |
| “Nudging is good because it helps people.” | Ethical evaluation requires criteria and multiple perspectives. |
16. Learning area at a glance
✏️ Practise it yourself – in the task generator
Generate practice tasks on the ultimatum game, sunk-cost bias, hyperbolic discounting, anchoring and nudging – with complete solutions and suitable for FOS/BOS Bavaria, IBV 11 and the curriculum valid from 2026/27.
Curriculum reference: FOS Bavaria, IBV 11 (IW), valid from school year 2026/27, Learning Area 4 “Understanding and optimising decisions from a behavioural economics perspective”, approx. 12 lessons.