# Designing behavior-change campaigns that actually shift public action
In the late 1990s, anti-smoking campaigns plastered billboards with blackened lungs and gravestones. The logic seemed airtight: scare people, and they quit. Except many did not. Some smokers looked at the fear imagery, felt anxious, then lit a cigarette to calm the anxiety. Fear alone can backfire, especially when the behavior itself is a coping mechanism.
This lesson is about what works instead. Public sector marketing is rarely about selling a product. It is about moving citizens from awareness to action and, harder still, to sustained action. That requires segmentationsegmentationDividing a market into distinct groups of customers who share similar needs, characteristics or behaviours, so each group can be served with a tailored approach.View full definition → and behavioral science, not just a louder message.
Fear grabs attention, but attention is not behavior. Three problems recur:
The lesson from decades of public health work: the most effective campaigns pair a small amount of emotional motivation with a concrete, low-friction action and social proofsocial proofThe tendency of people to look at others' choices to guide their own. In marketing, it means using reviews, testimonials, ratings and case studies to reassure and persuade prospects.View full definition → that others are already doing it. Australia's later tobacco control efforts, which combined graphic warnings with quit-line phone numbers and support services, are widely cited as more effective than fear imagery alone, because they gave people somewhere to go.
The biggest mistake in public campaigns is treating "the public" as one audience. Different people are at different stages and have different barriers.
A useful frame is the Stages of Change model (also called the Transtheoretical Model), which describes how people move through: precontemplation (not thinking about it), contemplation (considering it), preparation, action, and maintenance.
Your campaign job changes depending on the stage:
| Stage | What the audience needs |
|-------|------------------------|
| Precontemplation | A reason to care that connects to their values |
| Contemplation | Confidence it is possible and worth it |
| Preparation | A concrete plan and the tools to start |
| Action | Reminders, ease, and early wins |
| Maintenance | Reinforcement and identity ("I am a non-smoker") |
A single billboard cannot serve all five. So segment your audience by stage and by barrier, then design a distinct message for each.
Demographics (age, income, postcode) help with targeting, but barriers drive behavior. Ask: what actually stops this person from acting?
Example: a city wants residents to compost food waste.
Each barrier needs a different intervention. Fixing friction (free countertop bins) does nothing for Segment B, who need a belief shift. Matching intervention to barrier is the core skill.
A nudge is a small change to how a choice is presented that makes the desired action easier, without banning options or changing incentives much. The concept comes from behavioral economics, popularized by Thaler and Sunstein. Governments now run dedicated behavioral units, often called "nudge units," starting with the UK's Behavioural Insights Team.
Here are the nudges that reliably move public action.
People tend to stick with whatever option is preset. Organ donation rates are dramatically higher in countries with opt-out systems (you are a donor unless you say otherwise) than opt-in systems, though culture and infrastructure also play a role. If you want an outcome, make it the default and let people opt out.
People do what they believe others like them do. A widely cited series of experiments on household energy use found that telling people how their consumption compared to neighbors reduced usage more than appeals to save money or the planet. The message "most people in your area recycle" outperforms "you should recycle."
Caution: never advertise the bad behavior as common. Saying "too many people fail to vote" can normalize not voting. Frame the desired behavior as the norm.
Every extra click, form, or step loses people. The classic public sector example: tax authorities that pre-fill forms and send a simple, timely letter collect more on-time payments than those relying on long documents. The UK tax reminder that said most people in your area have already paid nudged behavior through both social proofsocial proofThe tendency of people to look at others' choices to guide their own. In marketing, it means using reviews, testimonials, ratings and case studies to reassure and persuade prospects.View full definition → and simplicity.
Ask people to specify when and where they will act. Voter turnout studies show that asking people to name their voting time and route increases follow-through compared with a generic reminder. "Make a plan" beats "please act."
🎬 [VIDEO: "How to Get People to Do What You Want (Nudge Theory)" — youtube.com — an accessible overview of behavioral nudges and how governments apply them]
A helpful design checklist is BJ Fogg's behavior model: a behavior happens when motivation, ability, and a prompt occur at the same moment. If action is not happening, one of the three is missing.
Applied example: a campaign encouraging flu vaccination among older adults.
Notice the small amount of emotion, paired with radical ease and a timely trigger. That is the opposite of the blackened-lung billboard.
Public budgets are accountable to taxpayers, so untested creative is a risk. Run small experiments first.
An A/B testA/B testA/B testing is a controlled experiment that compares two versions of something (A and B) by splitting traffic randomly to learn which performs better on a chosen metric.View full definition → compares two versions of a message with different audience groups to see which drives more action (calls, sign-ups, clicks). Even a low-cost test of two subject lines on an email or two versions of a letter can reveal large differences before you commit a full budget.
The Behavioural Insights Team publishes practical guidance on running these tests in government settings. Their EAST framework (Easy, Attractive, Social, Timely) is a free, plain-language checklist worth keeping on your desk.
Knowledge check
1. Why can fear-based messaging backfire when the targeted behavior is itself a coping mechanism?
2. A campaign manager notices that an aggressive 'you must stop now' message is producing resistance among the exact group they most want to reach. Which concept best explains this?
3. According to the lesson, what should be the FIRST step in designing an effective public behavior-change campaign?
4. Select ALL correct answers. Why does fear alone often fail to produce sustained behavior change?
Select all the correct answers.
5. Select ALL correct answers. What elements characterize the most effective behavior-change campaigns described in the lesson?
Select all the correct answers.
Awareness campaigns often celebrate a spike in sign-ups, then watch the behavior fade. Getting someone to try composting once is easy. Getting them to do it every week for a year is the real goal.
To sustain behavior:
Nonprofits face this acutely with donors and volunteers. A one-time donation is a transaction. A recurring monthly gift is a sustained behavior, and it is driven by the same tools: make it the default (suggest monthly first), reduce friction (save payment details), reinforce identity ("you are a monthly supporter"), and give feedback ("here is what your gift did").
Nudges are powerful, which makes ethics non-negotiable in the public sector. The standard is transparency and citizen benefit. A nudge should help people do what they already want to do or what serves the public good, not manipulate them toward the agency's convenience against their interest. Defaults should always be reversible. If you would be uncomfortable explaining the tactic publicly, do not use it.