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Mass media interventions report

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This is an executive summary of our investigation into mass media interventions

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The promise of mass media lies in its ability to reach a large audience, and to shift behavior by improving knowledge, awareness, and social attitudes towards particular areas of health. Mass media campaigns can operate via media including radio, TV, newspapers and the internet. They have been used for various purposes in high-income contexts, including reducing the use of tobacco and alcohol, promoting healthy eating, and increasing rates of cancer screening.

Estimating the potential impact of a mass media intervention involves estimating the degree to which a given media campaign changes behavior, as well as the causal effect of that behavior change upon relevant health metrics such as mortality. In this investigation, I show that (given the scale at which mass media campaigns operate) these campaigns can be cost-effective even if the expected changes upon behavior, and the corresponding effects of that behavior change upon mortality, are relatively small. I then examine the expected effect of mass media interventions upon behavior and health, primarily using existing evidence from randomized controlled trials (RCTs) in low and middle income countries (LMICs).

My power analyses find that existing RCTs are hugely underpowered to directly find effects of mass media upon mortality (including at effect sizes that my back-of-the-envelope-calculation (BOTEC) suggests would be highly cost-effective)—although many RCTs have successfully found differences in rates of health-relevant behaviors, such as rates of clinic visits or use of modern contraception, which they are better-powered to detect. My BOTECs therefore uses this evidence (alongside evidence from other sources about how changes in these behaviors affect mortality) to assess the impact of mass media interventions.

Overall, my BOTECs suggest that these interventions are cost effective (4x - 32x GiveDirectly), despite including large discounts (~40%) for generalisability. In addition, I also argue that there is reason to expect that a small number of mass media campaigns may generate long lasting impact, as knowledge (unlike say, a bednet) does not always disintegrate over time and can be freely passed onto others—a factor that has generally not been accounted for in existing work. There may be a small number of campaigns that shift entire group attitudes and behaviors (for example, contributing towards a change in social norms about contraception) that are hugely impactful.

Areas where mass media campaigns may be especially helpful include those where current misconceptions about health exist (for example, modern contraceptive methods), and where unhelpful social norms (such as the acceptability of intimate partner violence) persist. Given that current work suggests that the impact of mass media is very variable, I suggest that researchers attend to several features that have been linked to campaign effectiveness. These include cultural relevance, tackling misinformation or lack of information, and using these campaigns in areas where people have the resources to take the appropriate action. Examining these features with regards to particular campaigns may help grant-makers avoid donating funds to campaigns that are likely to have no impact.

Overall, I think that mass media campaigns are a promising—albeit risky—area for philanthropic donations. I am unsure about whether mass media campaigns are significantly underfunded in high income contexts, but it seems likely that they are underfunded in LMIC. Note that it is cheaper to run mass media campaigns in LMIC, where radio airtime is cheap, and there is some evidence that these interventions are especially effective in LMIC: experimental effect sizes have generally been larger in LMIC relative to HIC, despite stronger research designs in LMIC. I suspect that this is because there is ‘low-hanging fruit’ for mass media interventions in LMIC, in the sense that there are critical gaps in healthcare knowledge for many people in LMIC, who do not necessarily have easy access to high-quality healthcare information. I identify several charities operating in this area, but I do not have a strong sense of their existing RFF; I recommend proceeding to investigate these charities.


  1. I could not find broad data on people’s healthcare knowledge (for example, a survey of general healthcare knowledge across people living in different countries). However, while healthcare misconceptions are somewhat universal, I found a large number of examples of healthcare misconceptions in LMICs. For example, in prior work I came across the practice of infant oral mutilation in countries such as Tanzania, where traditional healers remove a child’s ‘tooth buds’ (emerging canine teeth) with a typically unsterilized tool, in the mistaken belief that this will prevent illness (Garve et al., 2016). Another example of a relatively common misconception in LMIC is that epilepsy is contagious (Newton & Garcia, 2012). There are many other misconceptions that I do not have space to list here, for example about albinism (Baker et al., 2010), effective contraceptive methods (Mbachu et al., 2021), and who is susceptible to COVID (Schmidt et al., 2020). I suspect that people living in LMIC often have more limited access to accurate healthcare information relative to people living in HIC, for example due to limited internet access; in 2019, only ~30% of people living in Sub-Saharan Africa used the internet (Individuals Using the Internet (% of Population) - Sub-Saharan Africa | Data, n.d.).

About the author


Rosie Bettle

Senior Researcher

Rosie is an Applied Researcher based in London, focusing on Global Health & Development. Before joining Founders Pledge in March 2022, she attained a PhD in Biopsychology from the University of Michigan; her published work is on the topic of cognitive evolution (and involved a lot of running around after monkeys). She has a masters degree in Human Evolutionary Biology from Harvard University, and her BA is in Biological Sciences, from Oxford University.