Summary of Nudge by Thaler & Sunstein (Summarised by Paul Arnold – Trainer & Facilitator –


Nudge – by Thaler & Sunstein

(Summarised by Paul Arnold – Trainer & Facilitator –

Content = ****   Readability = *** Clarity & Structure = ***



Small and often insignificant things can influence (or ‘nudge’) behaviour.


The book illustrates a number of key principles of behavioural economics, and then delves into a range of social issues that could benefit from nudges such as our finances, the environment, health and marriage (many of these are so nuanced that I have chosen not to review these chapters in depth but instead remain focused on the key principles of BE).





Choice architecture – The organizing of things can help influence decision-making (as it tends to focus attention). Thus there is no such thing as a neutral design. Many people are happy to accept the default settings/order provided by the Choice Architect, e.g. the settings on a phone/computer – people assume the experts who designed the equipment chose the ‘optimum’ settings so often do not change them. Thus the original set-up nudges people into a certain ways of operating with the technology.


Example: The school cafeteria – without changing the menu but simply shifting around the way the food was displayed influenced choice of various items by up to 25%


Example: Certain countries/states have an organ donation ‘opt out’ tick box on their driving license application form. Most people do not bother to opt out so the availability of donor organs is significantly higher than in those countries where the box is an ‘opt in’ box (e.g. in US states, 42% ‘opt in’ vs. 82% ‘opt out’).



The path of least resistance – Products/options that make life easier will be favoured. Conversely, if something is complex and difficult, then people are less likely to follow through e.g. insurance forms.


Example: Offering multiple corporate pension plan choices versus a limited number leads to a greater number of people not even registering for any pension plan.


Example: Giving students a map of how to get to the health center increased tetanus inoculations by 28% (vs. just 3% when only given a lecture).


Heuristics – We live in a complex world where we often rely on shortcuts to help us make sense of things (and hence influence our decisions). Often these short cuts help, but occasionally they can mislead us. Tversky & Kahneman (1974) identified 3 heuristics that can lead to biases – anchoring, availability and representativeness.


Anchoring – The perceived value of something can be steered (or ‘anchored’) by an initial, sometimes irrelevant activity.


Example: Students were asked two questions in random order: ‘How happy are you?’ and ‘How often are you dating?’ When asked in this order the correlation between the two was low (0.11), but when reversed the correlation was much higher (0.62) i.e. the ordering anchored their assessment of happiness to the frequency of dating.


Example: With charitable donations, people give more if the options range from $100 up to $5,000 than if the options range from $50 up to $150.


Availability – Events that more easily spring to mind (such as recent or traumatic events) will be more influential on our behaviour.


Example: Tornadoes and earthquakes receive inflated estimates of likelihood to die from versus the more common ones such as asthma.


Example: Stock market investing/Inflation in house prices was partly triggered by the relative impression of safety and guaranteed return stimulated by the multitude of conversations surrounding us all at the time.


Representativeness – Our over-reliance on stereotypes (based on past experience) gets us into trouble. Furthermore, we try to create (false) meaning out of randomness.


Example: Streak shooting in basketball is a well known concept, when players have a ‘hot-hand’ and thus score more points if they have shot successfully the last time. However, statistical studies have shown that hot hand is a myth.



Optimism and over-confidence – We often over-estimate our abilities to achieve things.


Example: 90% of US drivers think they are above average drivers. 94% of US professors at large universities believe they are better teachers than average.


Loss aversion – ‘Losing something’ is valued at least twice as highly as ‘gaining something’.


Example: ‘If you do not use energy conservation methods you will lose $350 a year’ is more effective at driving uptake than on ‘saving $350’.


Example: Pledge clubs where people will lose money if they do not deliver against their pledges (often to causes they are morally against).


Framing – The contextualizing of an issue can dramatically influence decision-making (e.g. when linked to either an anchor or loss aversion).


Example: Doctor says, “Of 100 patients who have this operation, 90 are alive five years later” vs. “of 100 patients who have this operation, 10 are dead five years later”. Even though the odds are exactly the same, the numbers agreeing to the operation are radically different.


Status quo bias – People tend to stick with their current situation that overcomes the inertia of change. So people rarely move their bank accounts or pensions or cancel initially enticing magazine subscriptions. NBC have discovered that once on a channel, people are more likely to stick with it than flick to a new channel (even though its so easy to do so).


Example: It’s easier to gain compliance to a medication if people have to take it everyday. Thus birth control pills, that are only required for 3 out of 4 weeks, maintains the daily regime by using placebos for 7 of the 28 days.


The emotion of decision-making – Our emotional state can influence our behaviour (cf shopping on an empty stomach). Thus people in an aroused state are more easily nudged.


Mindless choosing – We do many things on autopilot. For example most people eat in a mind-less trance.  Thus if we want to reduce our eating, techniques such as active attention and using small plate sizes help.


Example: Moviegoers were given a free bucket of popcorn. Some were given a big bucket, some a smaller one. Even though the popcorn was stale people with the big bucket consumed on average 53% more.



Mental accounting – Money is money – yet we often seem to have different ‘mental pockets’ we divide money up into – which can lead to some poor financial decisions being made. For example we may have cash in the bank but still have money outstanding on a credit card. Also we treat pay-rises and bonuses differently.


Many actions are divorced from their consequences (e.g. credit cards). However, sometimes if we could marry financial consequences more closely to action then it

would affect behaviour. For example, how would our behaviour change if the thermostat in our houses were to read the cost rather than the temperature?


Example: A city dweller, weighing up the merits of owning a car or relying on public transport and taxi’s will often treat the purchase price outside of the cost comparator.


Herd behaviour – We like to conform so are easily influenced by what others say and do (especially by those within the circle we wish to be associated with).  Social influence is one of the most effective ways to nudge behaviour.


Examples: The academic achievements of American students correlate closely with their roommates.

-Teenage girls who see other girls becoming pregnant are more likely to become pregnant themselves.

-Obesity is contagious (Those who eat regularly with another person eat 35% more – if four people, then we eat up to 75% more).


Example: Students invited into a room with five others. They are asked to match a line against one of three other choices (A, B or C). When the five others (all collaborators in the test) speak out the wrong answer, it makes the real respondent doubt his/her own answers.  In numerous tests, the respondents conformed with the others and gave the wrong answer between 20-40% of the time.


Example: In Minnesota, four different messages were tested to see which led to greater tax compliance. The idea that won was ‘Over 90% of Minnesotans paid their full taxes’.  The same principle was applied to reduce college drinking and teen smoking.


Example: San Marcos California energy bills graphically demonstrated if the household was using more or less energy than their neighbours by using a J or L.  This led to a dramatic reduction in energy usage.


Priming – Often seemingly irrelevant information can ‘prime’ a situation.


Example: The mere scent of an all-purpose cleaner encourages people to clean away their dishes after a meal.


Example: Asking people in advance of an election if they are going to vote increases the likelihood of voting by up to 25%.




Feedback – Quality, timely feedback helps to nudge behaviour. For example, digital cameras have improved the quality of picture taking due to instant feedback.


Reducing carbon emissions could be improved by providing a measurement system (such as Toxic release Inventory or the Greenhouse Gas Inventory). Ideally these measurement systems are best when converted into a measure that people already understand (like $).


Example: Southern California Edison gives out to its customers an ambient orb that flashes red when a customer is using a lot of energy and green when usage is modest. It has helped reduce energy consumption in peak periods by up to 40%.


Comparisons – It’s easier to make decisions when we make comparisons (cf all the comparison websites).  However it is important to note that different comparative sets can frame different decisions.


Sometimes too much choice can confuse, leading either to inaction or the making of sub-optimal decisions (as in the case of The USA ‘Part D’ of Medicare to allow people to devise their own drug prescription plan). Indeed many companies seem to make comparisons more obscure to help prevent making well-informed choices (cf mobile phone rates, mortgages etc).


Tversky recommends that when making complex decisions, focus on just the key criteria, and then set a minimal acceptable level for each criteria.


Some extra ‘mini nudges’ to help society

-Save money tomorrow – An automatic enrollment system, where the money is invested at source. Since pay rises are often mentally accounted for differently, the scheme ensures there is a commensurate increase taken into savings.


-Give money tomorrow – Works on a similar principle to the above where people make a future commitment to give money to a charity based on future pay rises.


-CARES – A stop smoking campaign where patients deposit the amount they would have spent on cigarettes in an account.  If clean from nicotine after 6 months they get the money back – otherwise it goes to charity. Evidence has shown this approach increases likelihood to quit by 53%.


-Healthcare plans – where premium is reduced if go to the gym etc to earn ‘vitality’ points.


-Civility check/24 hour delays on emails to ensure people do not over-react in the heat of the moment.



The Morality of nudging

The morality of influence is carefully side-stepped throughout the book by focusing on the concept of libertarian paternalism – i.e. it’s okay to influence decision-making if it makes their lives longer, healthier and better (even the term ‘nudge’ down plays the idea of unconscious influence). They argue that anyone who unscrupulously manipulates others for unfair gain will eventually be ‘caught out’.






An important book which brought the concept of behavioural economics to popular awareness.


The ongoing debate surrounding behavioural economics per se is in its application vis a vis the morality of unconscious influence.


Building from T&S’s concept of libertarian paternalism, one must ask. ‘Whose right is it to influence/decide what is best for another person?’


Recent research would suggest that nudging cannot be relied upon to provide consistent high levels of change.  Too many other factors are also involved and thus nudging is more likely to happen at the marginal level rather than having widespread effect.  Thus other actions can have a more profound effect on driving change such as legislation.















About slooowdown

Consultant in the fields of Relationships and Change
This entry was posted in Behaviour change, Behavioural Economics, Decision making, Leadership and tagged . Bookmark the permalink.

3 Responses to Summary of Nudge by Thaler & Sunstein (Summarised by Paul Arnold – Trainer & Facilitator –

  1. I never in a million years would have thought at things like
    this. This will make my day much easier.

  2. I really like reading a post that can make men and women think.
    Also, many thanks for allowing for me to comment!

  3. Pingback: BREAKING NEWS:Obabacare web site now operational - Page 2

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s