Editor’s Choice, December 2016: margins for shopkeepers or subsidies for consumers? What influence nutritious behaviour?

What do you think is most likely to increase uptake of fortified salt?   Consumer education leaflets?  Price cuts?  Incentives for shopkeepers?  Instead of making assumptions about what influences consumers to purchase food products that are good for their health, let’s find out!    

It’s rare for me to recommend an academic article as Editor’s Choice, and probably a first to be recommending an article on results of a randomised control trial.  But in  Movies, margins and marketing findings on what drove consumer adoption of fortified salt in India are truly fascinating.  The results are not necessarily applicable to other nutritious products or geographies, but they should make us all think harder.

Double fortified salt (fortified with both iodine and iron) was developed in India around a decade ago and uptake has been encouraged by the Government for several years.   The contribution of iodine and iron to health, and the technical issues around salt fortification are covered elsewhere.  This action research focused on 200 villages where the double fortified salt was on sale at a ‘research price’ of 9 Rs/Kg (regular salt is sold at around 10Rs/kg, while fortified salt is usually more expensive).    Within the 200 villages, different social marketing efforts were tested:

  • some shop-keepers were given higher margins on product sales
  • some villages were shown edutainment videos (involving Bhojpuri cinema stars)
  • some consumers were given informative leaflets
  • some consumers were given double fortified salt for free.

I’m not going to go into the design of the trial here, but this was a randomised control trial, in which each intervention (i.e. each marketing initiative) was randomly assigned, so that differences in outcome can be attributed to difference in intervention. The 200 villages were themselves part of a larger randomised trial. The authors from MIT and the Indian Institute of Management are leaders in this field, and considerably more detail is available in the source article.

Two interventions were found to be most effective:

  • showing the short film
  • offering an incentive to all shop-keepers in a village.

Each of these was shown to create a 50% increase in take-up of double fortified salt three years after launch, compared to villages with no intervention.

The role of shop-keepers was explored for good reason. In related research, 41% of households who bought DFS did so because this is what the shopkeeper gave them, and 8% because it is what he recommended.  But would shop-keepers respond to a 3Rs per kg incentive to sell this salt over alternatives?  The answer seemed to be yes.  The authors note that this won’t necessarily be true for other products: hairdressers incentivised to sell condoms showed little result, but persuading regular customers to shift their brand of salt seemed an easier task.

The edutainment movie was based on a sitcom.   Around 50,000 people in 64 of the villages saw it  – men, women and children, in late 2013.  In 64 villages, half of the participating households were given free double fortified salt. This was to test the ‘upper bounds’ of what could ever be achieved with marketing a priced product  (and data from these households also fed into other work on the efficacy of the salt on health).   3 years later, 55% of these households are using the salt.  Indeed, it’s well worth nothing that 45% don’t use it even when given it for free – that shows the scale of the challenge.   They reportedly gave it away, used it for animals, or for something else.

Leaving aside those who get the salt for free, typically just under 10% of households were using it, 2-3 years after it was introduced in their village.  20% had tried it.    Exposure to the movie increases both figures by about 50% (i.e. around 15% of households continued usage).  This is significant given they saw the movie only once, and uptake was measured 7 to 15 months later.  Digging into the data suggests it increased ‘willingness to accept’ the product (irrespective of different price points) rather than ‘willingness to pay’. 

A similar 50% increase in uptake was seen in villages where all retailers were offered the extra margin.    This intervention didn’t hugely change the number who tried salt once, but did increase the number that persisted with it.  Interestingly the effect was only seen where all retailers in a village had the incentive, not where only one did.  Anecdotally, shopkeepers that did not have the incentive were heard questioning the healthiness of the fortified salt, which would not only increase their own sales but make it harder for the incentivised shopkeeper to make the fortified salt the default or only option.

The flyer merely informed households about availability, rather than changing views of the product. It boosted uptake short term but not long term.

So if you are not selling fortified salt in an Indian village, what does this tell you?   That it’s complicated!   That it’s important to think about several aspects of the customer decision:

  • their perception of the product and who/what (e.g. soap opera stars) influence that
  • leaflets that simply provide information and don’t change attitudes may have limited value if attitudes have not been tackled first;
  • the point of sale moment, the role of retailers, and what will incentive retailers to leverage their power for beneficial products
  • price and subsidy – even when products come free, a large share of households don’t use them
  • the important difference between getting a share of customers to try it once, and a share of those to sustain purchase. Some strategies affect one more than the other.
  • the value of long-term research: results cannot just be transferred to other contexts and products, but they are food for thought. Or you can always explore a research partnership for yourself.


Further information

Movies, Margins and Marketing: Encouraging the Adoption of Iron-Fortified Salt, Abhijit Banerjee, Sharon Barnhardt, and Esther Duflo, published Oct 2015

There is a small but growing body of in-depth research on the role of different interventions on consumer uptake of products, services or good practice.   The authors note that In India, the introduction of cable television is associated with improvements in women’s status, including increases in reported autonomy and female school enrolment and decreases in the acceptability of beating. In the case of Brazil, exposure to Rede Globo soaps featuring very small families was found to decrease fertility by an amount equivalent to the mother having two extra years of education.

A different example is an impact assessment of Shamba Shake-up, looking at how radio programmes affect farmer practice in East Africa.  

GIF is funding Development Media International to explore role of radio in affecting uptake of contraception.

Use of data – or lack of it –  in inclusive business is a theme that we intend to explore further. Let us know if you are interested to contribute.


This blog is part of the December 2016 series on Inclusive Business models delivering nutrition, in partnership with DFID and GAIN. Don’t miss the webinar series in January 2017 on Marketing nutrition to the BOP.

Editor's Choice
Editor's Choice
As Editor of the Practitioner Hub I make an 'Editor's Choice' each month, to highlight a useful resource, document, tool, video, event or site to other inclusive business practitioners. There are some high quality resources on...

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