If context is king, why has nudging ignored it so much?

Updated: Mar 8

Part of Squared Away newsletter series on nudging

The key idea of behavioural economics and nudging is that our choices are strongly influenced by context yet there has been little systematic exploration of the broader environment in which decisions are made. In this post we'll take a step back from the immediate choice context to understand how the environment can make or break behaviour change interventions. The original article is written from a policy perspective, but with some adaptations the process also works for private sector behaviour change.


Successful behaviour change requires a good fit between interventions and the their environment. Sometimes a simple nudge-like intervention might be enough but without venturing beyond the immediate choice architecture, we risk misrepresenting the challenge we're trying to address and designing interventions that might fail. Having a taxonomy to identify environmental factors when designing interventions would provide clarity when they might fail. So, how might we characterise the circumstances in which nudges are appropriate?


No behavioural problem is an island

Nudges typically focus on the immediate choice architecture that includes the set of options available to the decision maker, and aim to overcome things that stand in the way of positive behaviour change by framing, highlighting or redesigning specific options.


However, every behavioural challenge is a causal structure extending way beyond the immediate choice architecture - not analysing problem in its environment inevitably limits the impact of an intervention. Thinking about what factors in the wider environment are contributing to a behaviour is a crucial starting point for identifying interventions and tailoring them to the problem.


In some ways, this isn't entirely new: the literature on behaviour change has been stressing the importance of starting from a multi-level analysis of the problem and integrating structural-environmental, psychological and behavioural factors. However, the behavioural economics research has been focused on the particular set of options that an individual decision maker faces without acknowledging or explicitly specifying the environment in which the choice architecture is embedded.

To me, it should be obvious that the success of a behavioural intervention can critically depend on societal and cultural factors as well as more tangible environmental factors that constrain the consequences of a decision-maker's choices*. The authors suggest these factors include economic, political and legal factors which reminded me of PESTLE, a tool used in strategic management to analyse the macro-environment for a company. Although their original definitions are slightly different, it could be a useful checklist for behaviour change practitioners too.


A good example of an intervention focused entirely on one part of the actual problem is the automatic enrollment onto organ donation. Looking at the wider environment would include considering the political and economic backdrop, cultural norms, legal systems, family veto rates as well as blackmarket economies. Alas, these are rarely mentioned when organ donation is used as an example of the power of defaults even though later analysis has shown that the number of registered organ donors is often only a proxy measure that doesn't necessarily result in more organ donations.


How to evaluate the environment of a potential intervention

Three questions will help us to assess the broader context for a behavioural intervention.


First, we need to decide what the ultimate goal of the intervention is and how we will measure its success. For example, is the goal to increase actual organ donations or just registered donors? Similarly, do you want to increase the number of people attending the gym or lower obesity levels in a population?


Second, we need to work out the sources of the problem and create a causal chain from individual behaviour to the goal. This should include the physical and social conditions needed for the behaviour change to happen - and most importantly whether the primary cause of the problem is psychological factors in the first place.


Third, think about potential interactions between the intervention and the environment - are there any parties who might try to counteract the intervention, opportunities that might compensate for the intended effect, or any differences in subpopulations that might need to be considered?


Exploring these issues helps determine what kind of environment the behavioural problem is embedded in, and whether nudges are likely to be effective. We can follow a process of asking specific questions to identify environmental factors that are critical to the success of interventions:

  1. Are the necessary physical and social preconditions missing in the environment?

  2. Are there parties in the environment with an interest to actively counteract the intervention?

  3. Does the environment contain factors that may compensate the intended effect?

  4. Are there individuating factors in the target population that could interfere with the intervention?

If the answer to all of the questions is 'no', we have an underutilized environment where simply focusing on the choice architecture is enough. Otherwise, we may also need to target other relevant factors in environments that are unprepared, counteracting, compensatory or heterogeneous.


Let's take a look at each in turn - starting from the most appropriate environment for nudges.


Underutilized environments

One reason behaviour change fails is that people overlook affordances in their environment - in this case, using the choice architecture might be enough.

For example, a lot of littering behaviour happens even though there are a lot of bins available which suggests that the main cause is not lack of facilities - people either actively avoid them or passively forget about them. In this case. In this case, behaviour change doesn't require any major changes in the environment (e.g. more bins) . Instead, we need interventions that target psychological barriers such as lack of attention or motivation and habits.


Here, the success depends on a good match between the root cause of the problem and the intervention


Unprepared environments

On the other hand, if the environment doesn't have the right facilities to support the behaviour, changing the choice architecture is unlikely to be enough.

For example, cycling to work instead of driving is increasingly popular but in many cities this motivation is overshadowed by fears for road safety and bike theft.

Therefore, the challenge of increasing cycling behaviour is not just rooted in the psychological barriers of an individual but primarily in the lack of infrastructure in the environment. That means any intervention that just focuses on the psychological causes of the problem (e.g. educational campaigns) is unlikely to succeed in changing behaviour.


Counteracting environments

There can also be environmental factors that prohibit or counteract the intervention's impact even if it might otherwise be effective in targeting the main factors contributing to the behavioural problem.


One example of this is overdraft fees in a situation where banks actively counteract the regulator's efforts. On the (slightly) bright side though, the same kind of behavioural intervention can lead to different results depending on the environment they are implemented in.


Compensatory environments

Sometimes the success of an intervention is hampered in a more subtle way when the desirable target behaviour is compensated for with something negative or undesirable.


A good example is the often referred to health nudge of rearranging items in a cafeteria to help people make better dietary choices. This intervention type targets the choice architecture by changing the order or the presentation of the food in a way that directs attention towards the healthier options. While this may result in some behavioural changes, the overall decrease in calories can be offset by the individual choosing other unhealthy items.


If you only target a small part of the choice environment, you're ignoring many factors that can undermine behavioural interventions unless accompanied by other "tools" (in policy these include e.g. taxes and bans) that help to eliminate the compensatory elements.


Heterogeneous environment

Many behavioural interventions are designed to target the largest number of people in one go as possible - after all, the promise of behavioural economics and nudging is that small changes can have big effects. This implicit universalist premise has long been "supported" by the lack of conclusive research evidence on individual differences in decision-making and as a consequence the question of whether subgroups might need to be considered has largely been ignored.


This assumption of sufficient homogeneity of behaviour and especially its underlying mechanisms has come at the expense of being sensitive to varying backgrounds, values and preferences of a particular population. In reality, effective behaviour change needs different interventions or combinations of them to deal with the same issue in different subgroups of the population.

For example, blanket media campaigns designed to get people to stop smoking tend to be less effective for socioeconomically disadvantaged groups which is particularly concerning because the prevalence of smoking is higher in this group - more effective campaigns tend to be combined with other interventions that support the behaviour change emotionally or physically.


Options for taking a more holistic approach

In addition to the guidance proposed by this paper, another option for characterising behaviour change interventions is the COM-B framework by Michie, van Stralen et al. (2011). Their system is focused on three factors and how they interact to produce behaviour: capability, opportunity and behaviour.


The most interesting contribution of this paper is that it focused on discussing external factors that are not under the individual decision-maker's control which fall under the Opportunity dimension. Of course, the COM-B model itself and the accompanying Theoretical Domains Framework do include many kinds of factors not addressed in this paper but this taxonomy is still a welcome addition to the discussion and help both practitioners and academic researchers to understand why the same intervention can have very different results in different contexts!



* behavioral economics refers to these as structural causes and public health researchers/sociologists as socio-ecological frameworks

If you want to read previous articles in this series:

  1. Going beyond System 1/2 - the many flavours and layers of decision-making psychology

  2. A peek under the bonnet - when and where are nudges effective?

  3. Are nudges always good and sludges always evil?

  4. Nudge, boost, budge and shove - what do they all mean?

  5. All that glitters is not gold - 8 ways behaviour change can fail

You can find more details and references in:

Meder, B., Fleischhut, N., & Osman, M. (2018). Beyond the confines of choice architecture: a critical analysis. Journal of Economic Psychology, 68, 36-44.


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