Transparency has long been proposed as the antidote to nudging’s ‘autonomy problem’. The worry is that nudges may bypass deliberate choice-making, and leave people feeling manipulated by steering behaviour without their awareness. The most popular response is simply to tell people they are being nudged through a disclosure message attached to the intervention. But does disclosing a nudge actually make people feel more in control? And how does it affect the nudge itself? In this blog post, Robin Cuypers argues the answer may be more complicated than we would like.
Why transparency might help or backfire
There are several underlying assumptions that influence how transparency may affect a nudge and people’s perceptions of their autonomy – negatively or positively.
On the one hand, disclosures might undermine a nudge when people realise they are being influenced and, as a result, feel manipulated. Awareness may trigger a fall in perceived autonomy, causing them to push back, reassert their independence, and deliberately choose the option they were nudged away from. A simplistic presence disclosure, which only tells someone that a behavioural technique is being used, may be enough to activate this resistance, or ‘psychological reactance’.
On the other hand, disclosures might enhance both perceived autonomy and the effectiveness of the nudge, if people feel more confident in their decisions. Several behavioural techniques, such as nudge plus or boosts, rely on the idea that behavioural interventions may be more effective when they engage deliberative thinking to boost decision-making. Self-determination theory suggests that people are more likely to engage with and internalise behaviours when they feel their autonomy is supported rather than bypassed. Disclosure messages may have these autonomy-enhancing effects. For instance, a purpose disclosure that explains why a nudge is being used, could encourage a more deliberate decision that feels genuine and autonomous. So which is it? Previous evidence finds little to no results from transparency, but disclosures vary heavily in the content of the disclosures, ranging from a simple acknowledgement that a nudge is being used, to messages that explain its purpose or describe how it works.
Four messages, one nudge
To test the effects of transparency, we conducted a vignette survey experiment with 1,916 participants. We presented respondents with a restaurant menu on which sustainable dishes were made more visually prominent through salience nudging techniques. We measured whether participants chose a sustainable dish and how they rated their own autonomy.
Participants were randomly assigned to one of six experimental conditions (see Table 1), which included four ways of disclosing the nudge to the participant. A presence disclosure simply informed participants that a behavioural technique was being used. A purpose disclosure added an explanation of the policy goal of promoting sustainable eating. A mechanism disclosure described how the nudge works, namely by making certain options more visually salient to exploit automatic cognitive shortcuts. A combined disclosure brought all three elements together in a single message.
Table 1: Experimental design and survey vignettes
| Group | Nudge? | Included a disclosure? |
| Control | No | No |
| Nudge | Yes | No |
| Presence | Yes | ‘We use behavioural insights to influence your choice.’ |
| Purpose | Yes | ‘We use behavioural insights to influence your choice towards more sustainable dishes.’ |
| Mechanism | Yes | ‘We use behavioural insights to make certain dishes more salient and influence your choice. We do this by calling them “chef’s choice”, placing them in a separate frame and showing sustainability scores.’ |
| Combined | Yes | We use behavioural insights to influence your choice towards more sustainable dishes by making those dishes more salient. We do this by calling them “chef’s choice”, placing them in a separate frame and showing sustainability scores.’ |
Figure 1: The vignette menu with nudge and combined disclosure
Source: Cuypers et al (2026)
Many possibilities, but no real effects from transparency
The nudge worked. Participants exposed to the salience nudge were significantly more likely to choose the sustainable option than those who were not. Strikingly, the nudge itself also produced a small but significant drop in perceived autonomy. People who were nudged felt, on average, slightly less autonomous in their food choice.
However, for all of the different disclosure messages we implemented, none had any significant effect on either food choice or perceived autonomy. Whether participants were told simply that a behavioural technique was being used, given the policy rationale behind it, shown a full explanation of the underlying mechanism or received all of this information combined, the nudge remained equally effective and perceived autonomy remained equally – if modestly – diminished.
Why is this? One might reasonably expect that more comprehensive disclosures would have a larger effect. For instance, explaining both the purpose and the mechanism of a nudge should give people greater insight about the intervention and their decision, and with it a greater sense of control. Yet the content of the disclosure appears to make very little difference.
Figure 2: Effectiveness of the nudge and perceived autonomy
Source: Cuypers et al (2026)
Transparency as the saviour of autonomy
These findings carry two implications. For policymakers, the message is reassuring in some ways. Disclosing a nudge will not make it less effective. Organisations that want to be more open about their use of behavioural tools need not fear that transparency will undo their efforts. This gives practitioners the opportunity to be more forthcoming by publishing information about their interventions.
Yet for the ethical debate, disclosures now seem insufficient. Transparency has been positioned as the key mechanism by which nudges can be made compatible with autonomy. Our results suggest that disclosure does not deliver on this promise. Knowing you are being nudged, and even knowing precisely how and why, does not appear to restore the sense of autonomous choice that nudges may sometimes erode.
Perhaps most notable is that the content of the disclosure appears not to matter. This may be because the disclosure messages had no effect on perceived autonomy, or it may be that attention to disclosures is too low for them to have any impact.
This does not mean transparency is worthless, but it does mean that disclosures alone may not be the answer to nudging’s autonomy problem. If the goal is to make people feel genuinely in control of their choices, we may need to look beyond the disclosure message – toward other means of transparency, and more broadly still at the relationship between citizens and the institutions that design their choice environment.
This post is based on the paper ‘Unpacking transparency in nudging: the impact of different disclosure messages on nudge effectiveness and perceived autonomy’ by Robin Cuypers, Pieter Raymaekers and Steven Van de Walle, published open access in Behavioural Public Policy.
Robin Cuypers is a doctoral researcher at the Public Governance Institute, KU Leuven.
Pieter Raymaekers is a researcher in behavioural public policy and administration and Lifelong Learning Coordinator at the Public Governance Institute, KU Leuven.
Steven Van de Walle is professor of public management at the Public Governance Institute, KU Leuven, whose research focuses on public sector reform and citizen–government interactions.