Increasing Health Savings by Using Anchors

The World Health Organization estimated that over 150,000 Kenyan children died from preventable causes in 2011 alone. One reason is that people simply cannot afford to get treatment for themselves or their children, particularly those living in the slums. A simple cough can quickly become pneumonia if untreated. When faced with a seemingly minor illness, parents making less than $1.50 a day have to make tough decisions between basic necessities like food, shelter, and medical care. Saving for health can be difficult, but life-saving.

M-TIBA is a free health savings wallet that is stored on a mobile phone. A Kenyan can sign up for M-TIBA and then save as little as 10 cents at a time, but this money can only be used for health expenses. If the individual saves one dollar in a month, then M-TIBA provides a bonus of 50 cents. The goal is to save little by little so that when a health issue arises, the individual can dip into the M-TIBA wallet to pay for medical care.

Unfortunately, while enrollment in M-TIBA has been high (over one million users since its start in May 2016), savings rates have been low. Most users have never saved in their health wallets. The Center for Advanced Hindsight’s Global Health and Development Team has worked with its partners, the PharmAccess Foundation and CarePay, to increase savings in these health wallets.

The Power of Anchoring

People are often influenced by the first piece of information that is offered (the “anchor”) when making decisions. They then base subsequent decisions on this anchor. For example, imagine a person sees a phone that costs $1,000 on a website. They are now anchored to this amount. Thus, if the person sees that the phone is selling for $900 a week later, she would think that this is a great deal.

The global team applied the insight of anchoring to the case of M-TIBA, hypothesizing that people are anchored to saving one dollar, since M-TIBA heavily promotes the bonus of 50 cents for a dollar saved. This amount might be too high, as the average Kenyan living in the slums of Nairobi makes less than $1.50 per day. If a person does not readily have one dollar to save, then this might be a barrier for depositing at all. A lower anchor might increase the number of users depositing by lowering that barrier. CAH and its partners decided to test this idea via text messages. M-TIBA users were sent two different text messages – one with an anchor of 10 cents and one with an anchor of one dollar:

  1. “Save 100 KSh in M-TIBA, and unlock 50 KSh bonus this month.”
  2. “Save as little as 10 KSh in M-TIBA, and unlock 50 KSh bonus if you save at least 100 KSh this month.”

As we hypothesized, the lower anchor increased the percentage of people saving: 3.4% saved in the 100 KSh (one dollar) anchor group while 4.8% saved in the 10 KSh (10 cent) anchor group. The lower anchor also increased the percentage of repeat savers from 0.6% to 1.1%. However, the lower anchor led to a lower amount of savings for those who actually saved: the most frequent deposit amount was 10 KSh in the low anchor group versus 100 KSh in the high anchor group. In addition, the median amount saved was 50 KSh in the low anchor group, compared with 100 KSh in the high anchor group.


These results illustrate the potentially powerful impact anchoring can have on saving. When considering any new product or intervention, one should pay special attention to the following:

  • Anchors can encourage or discourage people to save, so thought should be given to the initial amount that is asked. If it’s too high, people won’t save. If it’s too low, people may not save as much as they can. If possible, a test should be conducted to determine the optimal amount.
  • Anchors will also have an effect on the number of times people save, so it is important to find the balance between the number of user deposits and the amount saved.
  • Different anchors may be more appropriate for different objectives. A lower anchor may be more useful to get people to begin using a product or intervention, whereas a higher anchor may be better to increase savings among those already engaged.

Anchors offer a great tool for savings programs to increase engagement. In the case of M-TIBA, lowering the anchor provided a substantial increase in the number of savers, which is important considering the lack of even one-time depositors in the program. An increase in saving for health by those who are most vulnerable to health shocks provides a concrete way to lower the number of preventable deaths in Kenya. If a child gets sick, a parent who saved in M-TIBA little by little is more likely to immediately take the child to a clinic for treatment, so the cough never becomes pneumonia. The smallest change in the framing of the reminder can save lives.

Judson Bonick is a Senior Behavioral Researcher with the Global Team at The Center for Advanced Hindsight at Duke University.

Ting Jiang is Principal of Global Health and Development at The Center for Advanced Hindsight at Duke University, an applied behavioral science research lab that helps people be happier, healthier, and wealthier.