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

Over time, nudge has been accompanied by other terms such as boosts. In this article, I take a look at their definitions, differences and the contexts in which they would be most effective.

Maybe it's an occupational hazard of being a researcher or just my personality - in any case, I like being specific about terminology and definitions because skipping that step leads all too often to unnecessary disagreements. It also efficiently reveals premises and assumptions.

When it comes to nudging (in the broadest sense), understanding the conceptual distinctions and underlying mechanisms are the first step to working out what kind of intervention will work best in which circumstances. In this post, we will look at the differences between nudges and boost, and touch on budges and shoves at the end.

What's the difference between a nudge and a boost?

Before we dive into the papers, here's a quick recap on the original definition of a nudge by Thaler and Sunstein:

...any aspect of the choice architecture that alters people’s behavior in a predictable way without forbidding any options or significantly changing their economic incentives. To count as a mere nudge, the intervention must be easy and cheap to avoid.

Their definition is rooted in the one of the prominent schools of thought in the behavioural science - the heuristics and biases (H&B) program.

If you haven't yet, make a quick detour and read this introduction to the different views before reading on!

The H&B school starts from the assumption that people use limited sets of heuristics when making decisions - an assumption it shares with the fast and frugal (F&F) school of thought. The nudge approach builds on this by instrumentalising cognitive limitations to influence behaviour whereas boosts aim to help people overcome these limitations by expanding (boosting) their abilities to make decisions that are aligned with their goals. Additionally, boosts don't just target people's choice environment but also their heuristic repertoire (skillset)

More specifically, boost and nudges differ in several ways:

what the target of interventions is
the basic premise of the underpinning research
how the interventions are assumed to work
assumptions about cognitive architecture
goal and long-term effect of interventions
normative implications (addressed in future posts in this series)

Below is a summary reference of the differences between nudging and boosting - key points will be discussed in the article.

The original definition of nudge includes behavioural policies that don't coerce people or change their financial incentives - in short, the focus is on the external context in which people make decisions. This umbrella category includes both educative and non-educative nudges - the latter are considered to be the innovative core of nudging, so we'll focus on that first.

Nudges steer people towards a particular behaviour by creating environmental conditions that trigger a given heuristic strategy.

In contrast, boosts change behaviour by fostering people’s decision-making competences.

Non-educative nudges target behaviour by harnessing cognitive or motivational deficiencies such as inertia, procrastination and loss aversion to steer it in the desired direction. The choice architect skips over features over which people have explicit preferences (e.g. money, convenience, taste) and focuses on features of the choice environment that people claim not to care about such as position in a list or default settings. A key consideration is that the effect of the intervention needs to be easily reversible to preserve the individual's freedom of choice.

On the other hand, boosts are designed to enable specific behaviours through improving decision making and its outcomes by enlisting human cognition, the environment or both. Additionally, a boost's objective needs to be transparent to the person because they need to endorse it in order to engage with it - good examples of this include financial planning and healthy food choices.

Zooming in on theories underpinning nudges and boosts

The roots of the nudge approach lie in the dual-system processing view of the human cognitive architecture which suggests that those wanting to change behaviour can choose from one of two routes: engage System 2 and foster it or harness System 1 deficiencies.

Nudging typically takes the latter approach while attempts to strengthen System 2 are rare for conceptual and cost-efficiency reasons. First, the dual-process view proposes that our cognitive and motivational deficiencies are difficult to prevent and resistant to change - therefore, debiasing attempts are seen as pointless. Secondly, the unique selling point of nudges has specifically been their cost efficiency and large scale impact to produce maximum benefits compared to other options like educating the public or traditional economic policies.

In contrast to the singular theoretical perspective of nudging proponents, those advocating for boosting don't all share the same view of human decision making (see this post) but what they do agree on is that cognitive and motivational processes are malleable, and that existing mental tools can be enhanced by redesigning aspects of the external environment or by teaching people how to redesign them.

Some of the best nudges are boosts

Boosts and nudges are not always mutually exclusive and the purpose of distinguishing them in this kind of detail is to allow us to choose more wisely to have the most efficient solution in a specific situation.

The ultimate goal of boosts is to change behaviour by enhancing existing competencies or building new ones so that they remain stable over time. In other words, the desired behavioural effect of a boost should persist after the intervention is removed if the behaviour is aligned with a person's value system.

In contrast, nudges change behavior by adapting the choice architecture and leaving individual competences unchanged so when the intervention is removed, behaviour is likely to revert to the pre-nudging state. However, nudges that influence behaviour repeatedly may eventually create routines that survive over time - in those cases the nudge intervention has had a boosting side effect.

By changing the choice context and harnessing cognitive and motivational deficiencies to affect behaviour, the nudge inadvertently affects the cognitive and motivational processes themselves. The nudge has thus turned into a boost and had lasting effects.

Before we close the case on boosts, we need to quickly clarify some common misunderstandings about them:

They're not the same as school education because like nudges they should be informed by evidence from behavioural science.
They should aim to develop new motivational and decisional competences specifically in circumstances where a person has limited time or resources while preserving their personal agency and autonomy.
They also don't need to be costly - while they do often require some investments of time, effort and motivation from the individual and/or the policy maker, many are low cost.

Budges and shoves

The last two terms are more loosely connected to the debate on the nature of decision-making - they're more from the perspective of policy and as such less relevant for private sector practitioners but probably still useful to cover for completeness.

A budge is when insights from behavioural science are used by policy makers to decide where and how to regulate against undesirable private sector actions. An example would be regulating display of products near supermarket checkouts because confectionary companies have traditionally paid for that privilege in order to leverage certain human behavioural tendencies.

Finally, a shove is used to describe explicit regulation of individual behaviours in situations where the benefits to the individuals are perceived to outweigh the costs - e.g. a ban on smoking.

In conclusion?

If I'm honest, some of this theoretical discussion and debate feels slightly superfluous and an example of academic silos. I will talk about this more in later articles, but I can't help but think there is already a more comprehensive framework in the shape of the COM-B model, the Theoretical Domains Framework and the accompanying literature which gives guidance from a policy perspective and connects interventions more clearly and logically to the challenges they are attempting to solve.

If you want to read other articles in this series:

You can find more details and references in:

Grüne-Yanoff, T., Marchionni, C., & Feufel, M. (2018). TOWARD A FRAMEWORK FOR SELECTING BEHAVIOURAL POLICIES: HOW TO CHOOSE BETWEEN BOOSTS AND NUDGES. Economics and Philosophy,34(2), 243-266.
Hertwig, R., & Grüne-Yanoff, T. (2017). Nudging and boosting: Steering or empowering good decisions. Perspectives on Psychological Science, 12(6), 973-986.
Oliver, A. (2013). From Nudging to Budging: Using Behavioural Economics to Inform Public Sector Policy. Journal of Social Policy,42(4), 685-700. doi:10.1017/S0047279413000299
Oliver, Adam (2015) Nudging, shoving and budging: behavioural economic-informed policy. Public Administration, 93 (3). pp. 700-714. ISSN 0033-3298