Papers by Michael Sanders
This paper presents results from a large (43,387) nationwide randomized controlled trial in Guate... more This paper presents results from a large (43,387) nationwide randomized controlled trial in Guatemala that used reminders to promote tax compliance. The trial varied the letter received by taxpayers (individuals and firms) who had failed to pay their income tax for the 2013 tax year. Taxpayers were randomly allocated to receive either no letter, the letter originally used by the Guatemalan Tax Authority, or four letter variants adapted using behavioral design. The study finds that although all letters increased the rate of declaration, only two of the letters were successful at increasing the rate of payment and the average amount paid per letter received. The best performing treatments were a deterrent message
framing non-declaration as an intentional and deliberate
choice, rather than oversight (designed to overcome status
quo bias), and a social norms message that referred to the
64.5 percent of taxpayers that had already paid this tax (join the status quo). These two interventions increased the rate of payment as well as the average amount paid conditional on paying, overall more than tripling tax receipts. The paper estimates that if sent to all taxpayers in the sample, in 11weeks the social norms letter would have generated additional tax revenues of approximately US$760,000, which is 36 times the cost of sending the letters. The are persistent and remain at 12 month follow up, suggesting the letters are effective in increasing revenue for the tax authority rather than just bringing tax receipts forward
Provision of social norm feedback to high prescribers of antibiotics in general practice: a pragmatic national randomised controlled trial
Unnecessary antibiotic prescribing contributes to antimicrobial resistance. In this trial, we aim... more Unnecessary antibiotic prescribing contributes to antimicrobial resistance. In this trial, we aimed to reduce unnecessary prescriptions of antibiotics by general practitioners (GPs) in England.
Targeting voter registration with incentives: A randomized controlled trial of a lottery in a London borough
Does an incentive—in the form of a lottery—increase voter registration, particularly among poorer... more Does an incentive—in the form of a lottery—increase voter registration, particularly among poorer members of society? In the summer of 2012, two groups of 20,000 randomly selected households from a London Borough were informed that they would be placed into a prize draw if they registered to vote by 28 September 2012. One group was offered £5000 and the other £1000 while the remaining households in the borough received the standard letter with the same deadline but no lottery offer. The registration rates after the deadline were 46.2 per cent in the £1000 group and 46.6 per cent in the £1000 group compared to 44.7 in the control. Levels of registration in the two treatment groups are statistically different to the control, but not from each other. Households in poorer locations are more receptive of the lottery offer whereas there is no effect in places where richer households live. After the face-to-face canvass of all remaining non-registered households, which took place after the experiment, there were no statistically significant differences between the treatment groups and the control. The study builds on the work of Raja and Schaffner (2012) and Panagopoulos (2013) by finding that incentives work in different ways depending on their level and who is targeted.
Stating Appointment Costs in SMS Reminders Reduces Missed Hospital Appointments: Findings from Two Randomised Controlled Trials
Background
Missed hospital appointments are a major cause of inefficiency worldwide. Healthcare p... more Background
Missed hospital appointments are a major cause of inefficiency worldwide. Healthcare providers are increasingly using Short Message Service reminders to reduce ‘Did Not Attend’ (DNA) rates. Systematic reviews show that sending such reminders is effective, but there is no evidence on whether their impact is affected by their content. Accordingly, we undertook two randomised controlled trials that tested the impact of rephrasing appointment reminders on DNA rates in the United Kingdom.
Experiments in both the lab and the field have gone some distance to proving that people are reci... more Experiments in both the lab and the field have gone some distance to proving that people are reciprocal agents,
returning one good deed with another, even when it is disproportionately costly to do so. This finding is increasingly
being applied to improve relationships between government and citizens, and to facilitate the smoother running of
public services. We investigate the extent to which interventions intended to induce reciprocity work in the longer
term, by asking participants to donate a comparatively large sum of money (£515 on average), to charity, after
receiving a small gift (a packet of sweets). We find that people given a small packet of sweets by a volunteer are
significantly more likely to donate to charity than those given a flier, and those not greeted by a volunteer. We find
that our initial results replicate successfully on participants who were not treated in the initial experiment. Our
principal contribution, however is to show that these effects fall by more than half the second time a participant
receives a gift, although it remains of net financial benefit for the charit
Randomised trials in education research are a valuable and increasingly common part of the resear... more Randomised trials in education research are a valuable and increasingly common part of the research landscape. Choosing a sample size large enough to detect an effect but small enough to make the trial workable is a vital component. In the absence of a crystal ball, rules of thumb are often relied upon. In this paper, we offer criticism for commonly used rules of thumb and show that effect sizes that can be realistically expected in education research are much more modest than studies are powered to detect. This has important implications for future trials, which should arguably be larger, and for the interpretation of prior, underpowered research.
When and how should a fundraiser ask for a donation from an individual facing an uncertain bonus... more When and how should a fundraiser ask for a donation from an individual facing an uncertain bonus income? A standard model of expected utility over outcomes predicts that the individual’s before choice – her ex-ante commitment conditional on her income – will be the same as her choice after the income has been revealed. Deciding “if you win, how much will you donate?” involves a commitment (i) over a donation for a state of the world that may not be realized and (ii) over uncertain income. Models involving reference-dependent utility, tangibility, and self-signaling predict more giving before, while theories of affect predict more giving after. In our online field experiment at a UK university, as well as in our laboratory experiments in Germany, charitable giving was significantly larger in the Before treatment than in the After treatment for male subjects, with a significant gender differential. Lab treatments isolated distinct mechanisms: for men, donations were higher in all treatments where the donation’s collection was uncertain, whether or not the income was known. This supports a (self)-signaling explanation: commitments realized with a lower probability must involve larger amounts to have the same signaling power. Our results are directly relevant to fundraising and volunteer-recruitment strategies, and offer further evidence that we need to exercise caution in applying expected-utility theory in the presence of social preferences.
Roughly 20% of adults in the OECD lack basic numeracy and literacy skills. In the UK, many colleg... more Roughly 20% of adults in the OECD lack basic numeracy and literacy skills. In the UK, many colleges offer fully government subsidized adult education programs to improve these skills. Constructing a unique dataset consisting of weekly attendance records for 1179 students, we find that approximately 25% of learners stop attending these programs in the first ten weeks and that average attendance rates deteriorate by 20% in that time. We implement a large-scale field experiment in which we send encouraging text messages to students. Our initial results show that these simple text messages reduce the proportion of students that stop attending by 36% and lead to a 7% increase in average attendance relative to the control group. The effects on attendance rates persist through the three weeks of available data following the initial intervention.
Finding a job, especially in a recovering economy, is challenging and success is reliant upon eff... more Finding a job, especially in a recovering economy, is challenging and success is reliant upon effective job-search activity. Jobseekers Allowance (JSA) welfare benefit claimants in the United Kingdom have many competing options available to them in terms of how they direct their efforts in looking
for work. Often it is hard to determine which is most productive. Unsurprisingly, Jobcentres – the
organisations that support JSA claimants during their unemployment – themselves have very strong links to the labour market. For example, they are often invited to run recruitment events in direct partnership with large employers seeking to hire in bulk. At Bedford Jobcentre, we observe that,
despite the relatively high likelihood of gaining work from attending such events, jobseeker attendance rates are still low and, instead, we can only assume that jobseekers may be taking part in less productive work search activities. This paper reports the results of a randomised control trial
designed to test the effectiveness of mobile phone text messaging in compelling jobseekers in the Bedford area to attend such events. Tailored text messages are found to significantly increase the likelihood of attendance. We find text messages to be particularly effective when they evoke a sense of reciprocity in the recipient.
Using a survey conducted during trick-or-treating at Halloween, we explore whether parental rules... more Using a survey conducted during trick-or-treating at Halloween, we explore whether parental rules serve merely to restrict children’s undesirable behavior or also to teach them values. We use two questions to identify children whose parents have rules for eating candy: Are they told they cannot eat any candy until they get home? Are there rules for how they should eat their candy after they get home? After administering the survey, we give children a choice of fruit or candy. We find that children whose parents set candy-eating rules are more likely to choose fruit. We argue that this is evidence that rules serve to create values, which children act on even when not directly monitored by their parents. We also find that having rules is correlated with children’s lack of self-control, suggesting that parents may put rules in place specifically to counteract their children’s self-control deficits. We also discuss alternative interpretations, for which there are many
Recent years have seen a growth in the use of social norm messages by local and national governme... more Recent years have seen a growth in the use of social norm messages by local and national governments. These messages have been primarily used to induce desired behaviours among the non-compliant minority by pointing to the compliance of the majority. As well as being of considerable theoretical interest, these messages have an unusually high level of empirical and experimental support in government settings. In this paper, we review many of these applied experiments in a bid to understand the workings of social norm messages and, just as importantly, where they do not work as well. We also discuss why this kind of intervention has attracted such an unusually large body of experimental evidence.
Nudges" -small, usually cheap, interventions to alter the behaviour of individuals to improve the... more Nudges" -small, usually cheap, interventions to alter the behaviour of individuals to improve their "health, wealth or happiness", are increasingly popular with governments and have thus far played a large role in the coalition government's attempts to encourage prosocial behaviour. The power of many of these nudges, such as the effect of priming in a trust-game type scenario, has been tested widely in the lab, but have proven difficult to replicate in the field. Although the laboratory allows a sterile environment, this is not always desirable -the real world is not sterile, and there are often many different factors competing for an individual's attention. We present the results of an experiment conducted during the course of a busy public * I am very grateful for the assistance of Alistair Jacklin, Harriet Robinson, Mike Peacey and Jonathon Grose for their assistance in the running of this experiment. I am also grateful to Julie Steen and Matt Harper of Bristol's IT Services for assembling the technology to make it possible, and to Dane Comerford and others at the Centre for Public Engagement for making the entire event possible. Many thanks are also due to David Reinstein of the University of Essex, Jamie Foehl of the Centre for Advanced Hindsight, and Elspeth Kirkamn from the Behavioural Insights Team for comments on early drafts. Any remaining errors are my own.
Using a unique field experiment we show that prompts to leave money to charity during the will-ma... more Using a unique field experiment we show that prompts to leave money to charity during the will-making process substantially increase the probability of making a bequest. Asking if the donor wants to leave money to charity doubles the proportion making a bequest; adding emotional and social cues trebles it. The responses are strongest among childless people. We compare the effects of the prompts to the effect of an estates tax. Our results suggest that both economic and non-pecuniary incentives similarly affect whether people leave money to charity, but are less effective where people have strong preferences for other bequests.
Giving has been shown by many studies to be a social phenomenon. However, while people may desire... more Giving has been shown by many studies to be a social phenomenon. However, while people may desire to conform to the donation of others, it is unclear how fundraisers should take advantage of this. In this paper we conduct a field experiment in a workplace, in which employees are sent prominent messages from a colleague who is already a donor. We find that signups for workplace giving more than double when a picture of the existing donor is displayed, relative to a message without a picture.
We report the results of a pilot study to test the impact of a short talk on pupils' stated inten... more We report the results of a pilot study to test the impact of a short talk on pupils' stated intentions to attend university. In this study, conducted over a single day in a single school, we test first the effect of mentoring vs no mentoring, and a variation in the form of the mentoring. We find increases in stated likelihood of applying to both university in general (0.8s.d.) and the University of Bristol particularly (0.0s.d.). We find no impact of varying the length of the talk.
Over the last few months Freebridge Community Housing have been working with the Cabinet Office B... more Over the last few months Freebridge Community Housing have been working with the Cabinet Office Behavioural Insights Team on a project to improve the social and environmental conditions at Hillington Square. This work sits alongside the regeneration of the properties – so as well as improving the physical appearance of the Square, we are also equally committed to developing the community.
Harvard Business School Working Paper Series
Many organisations, including corporations and governments, wish to encourage charitable giving, ... more Many organisations, including corporations and governments, wish to encourage charitable giving, and offer incentives for their employees, customers and citizens to do so. The most common of these incentives is a match rate, where the organisation agrees to pay, for example, $1 for every $1 donated. However, these incentives may not be efficient. In this short article we suggest alternative ways of matching that existing theory and data suggest might be more effective at encouraging donations. These include non-linear matching, social (and team) matching, and lottery matching – each of which novel schemes could be tested empirically against a standard match incentive.
Previous work on charitable giving has offered explanations for behaviour under anonymity, in lin... more Previous work on charitable giving has offered explanations for behaviour under anonymity, in line with game-theoretic models of freeriding, generally finding that if an individual is under less scrutiny, they are less likely to cooperate.These explanations do not answer questions as to why an individual would choose both to donate and to be anonymous. We present some stylised facts of anonymity, drawn from a large dataset of donations to the London Marathon, and develop a signalling model consistent with its findings..
Policy Papers by Michael Sanders
In this paper we evaluate the effectiveness of volunteering activities for young people at improv... more In this paper we evaluate the effectiveness of volunteering activities for young people at improving their non cognitive skills and other employability measures, including a Trier social stress test, in three randomised trials in the UK. We find significant improvements in non cognitive skills but more most (but indicative) improvements in performance in an interview measure.
Applying Behavioural Insights to Charitable Giving
https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/203286/BIT_Charitable_Giving_Paper.pdf, May 2013
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Papers by Michael Sanders
framing non-declaration as an intentional and deliberate
choice, rather than oversight (designed to overcome status
quo bias), and a social norms message that referred to the
64.5 percent of taxpayers that had already paid this tax (join the status quo). These two interventions increased the rate of payment as well as the average amount paid conditional on paying, overall more than tripling tax receipts. The paper estimates that if sent to all taxpayers in the sample, in 11weeks the social norms letter would have generated additional tax revenues of approximately US$760,000, which is 36 times the cost of sending the letters. The are persistent and remain at 12 month follow up, suggesting the letters are effective in increasing revenue for the tax authority rather than just bringing tax receipts forward
Missed hospital appointments are a major cause of inefficiency worldwide. Healthcare providers are increasingly using Short Message Service reminders to reduce ‘Did Not Attend’ (DNA) rates. Systematic reviews show that sending such reminders is effective, but there is no evidence on whether their impact is affected by their content. Accordingly, we undertook two randomised controlled trials that tested the impact of rephrasing appointment reminders on DNA rates in the United Kingdom.
returning one good deed with another, even when it is disproportionately costly to do so. This finding is increasingly
being applied to improve relationships between government and citizens, and to facilitate the smoother running of
public services. We investigate the extent to which interventions intended to induce reciprocity work in the longer
term, by asking participants to donate a comparatively large sum of money (£515 on average), to charity, after
receiving a small gift (a packet of sweets). We find that people given a small packet of sweets by a volunteer are
significantly more likely to donate to charity than those given a flier, and those not greeted by a volunteer. We find
that our initial results replicate successfully on participants who were not treated in the initial experiment. Our
principal contribution, however is to show that these effects fall by more than half the second time a participant
receives a gift, although it remains of net financial benefit for the charit
for work. Often it is hard to determine which is most productive. Unsurprisingly, Jobcentres – the
organisations that support JSA claimants during their unemployment – themselves have very strong links to the labour market. For example, they are often invited to run recruitment events in direct partnership with large employers seeking to hire in bulk. At Bedford Jobcentre, we observe that,
despite the relatively high likelihood of gaining work from attending such events, jobseeker attendance rates are still low and, instead, we can only assume that jobseekers may be taking part in less productive work search activities. This paper reports the results of a randomised control trial
designed to test the effectiveness of mobile phone text messaging in compelling jobseekers in the Bedford area to attend such events. Tailored text messages are found to significantly increase the likelihood of attendance. We find text messages to be particularly effective when they evoke a sense of reciprocity in the recipient.
Policy Papers by Michael Sanders