If people do not choose perfectly, then the way choices are laid out in front of them changes what they pick. That is the whole idea behind choice architecture and nudging — and it is why the salad is at the start of the buffet and the chocolate is at the till.
📚 What you need to know
Choice architecture is the deliberate design of how choices are presented, in order to influence what people pick.
Three types you must know: default choice, restricted choice and mandated choice.
A nudge is a small prompt that changes behaviour without removing any options and without changing prices.
If it bans something or taxes it, it is not a nudge. That is the line examiners test.
Richard Thaler popularised nudge theory; the UK Behavioural Insights Team uses the EAST framework — Easy, Attractive, Social, Timely.
Nudges are cheap and keep freedom of choice, but raise real worries about manipulation, transparency and consent.
Choice architecture: the layout is never neutral
Here is the point students miss. There is no such thing as presenting choices neutrally. Something has to go first on the menu. Something has to sit at eye level. Some box has to be ticked or unticked when the form loads. Whoever designs that layout is a choice architect, whether they meant to be or not.
Once you accept that, the question stops being “should we influence people?” and becomes “since we cannot avoid influencing them, which way should we point?”
This is the strongest defence of nudging and it is worth memorising. You cannot opt out of choice architecture, so the only real choice is whether it is designed carelessly or on purpose.
The three types
Type
How it works
Example
Default choice
An option is selected for you in advance. You keep the right to change it, but most people never do
A pension scheme where new staff are enrolled automatically unless they opt out
Restricted choice
The number of options is cut down, so the decision is simpler and the worst options are gone
A school canteen that stocks water and milk but not fizzy drinks
Mandated choice
You cannot move on until you actively pick. Nothing is chosen for you
A licence form that will not submit until you answer yes or no to organ donation
Use this scale to test any policy in an exam question. If an option was removed or a price was changed, it is not a nudge.
Nudge theory
A nudge is a small change to the environment around a decision that makes a particular option more likely, while leaving every option open and every price the same. Richard Thaler, who won the Nobel Prize for this work, argued that firms and governments should use nudges openly and responsibly rather than pretending they are not steering anyone.
The three-part test for a nudge
every option still available + no change in price + a predictable push in one direction
Why defaults are so powerful
The single most reliable nudge is changing what happens when you do nothing. Doing nothing is easy, doing nothing feels safe, and a pre-ticked box carries a quiet suggestion that this is what sensible people choose. Study after study finds the same shape of result: switch a scheme from opt-in to opt-out and sign-up rates jump, even though the choice itself has not changed at all.
The bars show the shape of the result, not exact figures. The point is the size of the gap given that no option, price or piece of information changed.
The EAST framework
The UK Behavioural Insights Team boiled good nudge design down to four words. It is a handy checklist if a question asks you to design one.
Easy — strip out effort. Shorter forms, fewer clicks, a helpful default.
Attractive — make it stand out and feel personal. A letter with your name on it beats a leaflet.
Social — tell people what others do. “Nine in ten neighbours have already paid” works because we copy each other.
Timely — catch people when they are open to change, such as a reminder the day before a deadline.
Everyday nudges to quote: the salad bar placed first, healthier food at eye level, a “baby on board” badge that prompts commuters to give up a seat, an energy bill that compares your usage with similar homes, and a pre-ticked donation box at a checkout.
Evaluating nudges
An evaluate question is not asking you to like or dislike nudges. It is asking you to weigh the gains against the costs and reach a supported judgement.
In favour
Against
Cheap. Reordering a shelf or reprinting a form costs almost nothing next to a subsidy or an enforcement programme
Manipulation. Nudges work by using a weakness in our thinking, and people have not consented to that
Freedom of choice survives. Nobody is stopped from doing anything, which makes nudges politically easy to pass
Lack of transparency. A good nudge often works best when you do not notice it, which is uncomfortable in a democracy
Health and environmental gains. Useful where the problem is habit rather than price, such as eating or recycling
Unintended consequences. Once people expect to be nudged, some deliberately push back and pick the non-default option
Simplifies hard decisions such as pensions or insurance, where imperfect information is the real barrier
Unreliable size of effect. Results vary with culture and circumstance, so a nudge that works in one country may fail in another
A judgement examiners reward: nudges are strong on cheapness and freedom, but weak on size and certainty of effect. So they work best alongside taxes and regulation, not instead of them.
Worked examples
WORKED EXAMPLE 1
A government wants more people saving into a pension. It changes the enrolment form so staff are signed up automatically unless they tick to leave. Explain why this is a nudge and not regulation. [4]
Step 1: identify the tool
This is a default choice, a form of choice architecture.
Step 2: apply the test for a nudge
No option has been removed — staff can still leave the scheme. No price has changed — there is no tax or subsidy attached.
Step 3: explain why it still works
Because of inertia and bounded rationality, most people accept whatever requires no action, so enrolment rises sharply.
It steers the decision while leaving freedom of choice intact, so it is a nudgeRegulation would have made saving compulsory. That is the contrast the question wants.
WORKED EXAMPLE 2
Evaluate the use of nudges rather than taxation to reduce sugar consumption. [10]
Step 1: one strong point for nudges
They are cheap to run and keep freedom of choice, so there is no loss of consumer surplus and little political resistance.
Step 2: one strong point againstDemand for sugary drinks is price inelastic and habit-driven, so a shelf change may shift only a small number of buyers, while a tax raises revenue that can fund health programmes.
Step 3: bring in the risk
Nudge effects vary between groups and can fade once people notice them; tax effects are more predictable.
Step 4: judgementNudges are a useful low-cost supplement, but a tax is more reliable where the harm is largeJudgement means picking a side and saying on what it depends. Sitting on the fence scores badly.
💡 Exam tip
Test every policy against the definition. Option removed or price changed? Then it is not a nudge.
Name the type — default, restricted or mandated. Vague answers about “changing the layout” lose the mark.
Link each nudge back to a limitation from the previous page. That is where the analysis marks are.
For evaluation, compare nudges with the alternative policy in the question, not with doing nothing.
Use the word inertia when explaining defaults. It is precise and examiners recognise it.
Finish with a judgement that says it depends on what — usually the size of the harm and the elasticity of demand.
⚠️ Common mix-up
Calling a sugar tax a nudge. It changes price, so it is an incentive.
Calling a ban a nudge. It removes options, so it is regulation.
Mixing up restricted and mandated choice. Restricted takes options away; mandated forces you to pick from the same set.
Assuming nudges always help the consumer. Firms use the same tools to raise their own profit, which is why the ethics point matters.
Writing a list of examples with no theory. Every example needs the underlying bias named.
Forgetting that nudges are HL only. Do not build an SL answer around them.
Up next: Business Objectives Beyond Profit — we have questioned whether consumers maximise. Now we turn the same question on firms. Do they really produce where MC = MR?
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