Key Takeaways

• Overall, our view is that advocacy for a long-term public education campaign to address low physical activity might be an extremely cost-effective cause area.
• However, with respect to the scientific evidence, while the link between physical inactivity and disease is indisputable, there is considerable uncertainty as to effectiveness of specific interventions like mass media and community-based interventions in actually increasing physical activity levels.
• Additionally, while the experts we consulted unanimously agreed that the global burden of physical inactivity will continue to grow, there was more disagreement over the best way to counter this. Overall, they leaned in favour of taking a population-level approach, but experts also flagged out that this is hard to do or sustain. This is especially so from a historical perspective, given that leisure-time physical activity has not been how humans have actually gotten sufficient physical activity (vs being active due to work and chores).
• At the same time, the downsides to addressing physical inactivity as a cause area are minimal, even less so than other areas like nutrition policy, where questions of infringing upon people's freedom of choice or having perverse policy consequences do not even arise.

Executive Summary

Taking into account (a) the expected benefits of addressing low physical activity, in terms of improved health and increased income, while also factoring in (b) the expected costs on the economic front and (c) the tractability of advocacy for a long-term public education campaign to increase physical activity, CEARCH finds the marginal expected value of advocacy for such a long-term public education campaign to address low physical activity to be 12,065 DALYs per USD 100,000, which is around 10x as cost-effective as giving to a GiveWell top charity – which are themselves some of the very best in the world. (CEA).

See short report here.
 

• Introduction: This report on low physical activity is the culmination of two iterative rounds of research: (i) an initial shallow research round involving 1 week of desktop research; and (ii) a subsequent intermediate research round involving 2 weeks of desktop research and expert interviews;
   
• Importance: Physical inactivity is a risk factor for multiple diseases, including heart disease, diabetes, stroke, and cancer. Globally, low physical activity is certainly a problem, and will have a direct health burden of 19 million disability-adjusted life years (DALYs) in 2025, as well as an indirect health burden of 60,000 DALYs via an increased risk of depression. There is also an accompanying net economic burden equivalent to foregoing the doubling of income for 14 million people; note that people typically value such income doublings at around 1/5th of a year of healthy life. And this problem of physical inactivity is only expected to grow between 2025 and 2100, as a result of factors like urbanization, ageing, and population growth.
   
• Neglectedness: Government policy is far from adequate, with only 10% of countries implementing the top WHO-recommended policy of a long-term public education campaign to promote physical activity; this is not expected to change much going forward – based on the historical track record, any individual country has only a 0.1% chance per annum of introducing this recommended policy. There is, of course, significant heterogeneity – some countries like Singapore have a good strategy in place, but other countries (e.g. Australia, US, Germany) are nowhere near this, and compared to such high-income countries, developing countries fare even worse.
   
• Tractability: There are many potential solutions to the problem of low physical activity (e.g. a public education campaign; built environment interventions to make cities more walkable; digital interventions like apps and wearables; and point-of-decision prompts like posters by staircases); however, we find that the most cost-effective solution is likely to be advocacy for a public education campaign to promote physical activity; this campaign is inclusive of both a mass media campaign and accompanying community-based interventions such as a pedometer-based National Steps Challenge. The theory of change behind this intervention is as such:
  
  
  • Step 1: Lobby a government to implement a long-term public education campaign to increase physical activity.
  • Step 2(a): The mass media campaign component of the long-term public education campaign in a single country reduces physical inactivity and its related global disease burden.
  • Step 2(b)(i): The community component of the long-term public education campaign in a single country increases physical activity in a single country.
  • Step 2(b)(ii): Increased physical activity from the community component reduces the global disease burden of low physical activity.
     
• Using the track record of past walkability policy and nutrition policy advocacy efforts and of general lobbying attempts (i.e. an "outside view"), and combining this with reasoning through the particulars of the case (i.e. an "inside view"), even while adjusting for counterfactuals, our best guess is that funding advocacy campaigns will have an 11% chance of successfully enacting a long-term public education campaign to increase physical activity. Meanwhile, based on various meta-analyses, and after robust discounts and checks (e.g. for a conservative theoretical prior of a null hypothesis; for endogeneity; for study populations being unrepresentative; or for publication bias), we expect that a mass media campaign in a single country will reduce the global disease burden of low physical activity by 0.07%; that a community-based intervention (particularly a pedometer-based national challenge) can increase participants' average number of daily steps by 1000, which will in turn reduce the global disease burden of low physical activity by 0.0005%. Note that while the WHO recommends a holistic approach, we expect the mass media campaign to have the bulk of the impact.
   
• There are additional complications to the intervention. In particular, we expect on average a 7 year gap between when an advocacy intervention begins and when the health impact actually kicks in (-12% impact).
   
• Outstanding Uncertainties: There are a number of outstanding uncertainties, of which the four most important involve: (a) our use of point estimations (n.b. relying on them is reasonable given that we are ultimately interested in mean estimates, but caution is also warranted, as significant variance is possible); (b) the very simplified methodology we use to project the future disease burden of low physical activity; and (c) the massively complicated extrapolations we had to make in calculating the effect sizes of a mass media and pedometer campaigns; and (d) the highly uncertain estimates of the probability of advocacy success.

• Conclusion: Overall, our view is that advocacy for a long-term public education campaign to address low physical activity might be an extremely cost-effective cause area, but more research is needed.