Over the past two decades, global health has undergone a profound transformation. As public funding for international health and development has become increasingly unpredictable, private philanthropy has largely stepped in to fund global programmes.It is well known that large foundations, such as the Gates Foundation, Bloomberg Philanthropies, or the Chan Zuckerberg Initiative, to list a few, now largely contribute to the budgets of the World Health Organization (WHO), a number of public-private partnerships, or initiate private initiatives.What is less visible though is the way philanthropic organisations are increasingly producing the data, research, and knowledge infrastructures through which global health problems are known, prioritised and eventually governed. This shift is often presented as pragmatic, in the face of constrained budgets and an urgent global health crisis. Yet the expanding epistemic presence of philanthropic actors in global health is interrogating, when it shapes the very frameworks though which health issues are understood.When philanthropic foundations produce global health dataPhilanthropic foundations have, in recent years, widely invested in the production of metrics on the “burden” of specific health conditions and the “costs” and “returns” of given health interventions.These metrics, while necessary, do not only describe reality, but define what counts as a health problem and what kinds of interventions are deemed valuable.In 2007, the Gates Foundation (formerly known as the Bill & Melinda Gates Foundation) created the Institute of Health Metrics and Evaluation (IHME) to provide “timely, relevant, and scientifically valid evidence to improve health policy and practice” (IHME website).Since its establishment, the IHME’s has been calculating the so-called Global Burden of Disease (GBD) metrics.The GBD is the largest-scale project ever set up aimed at measuring morbidity and mortality rates throughout the globe using the metric of DALYs (Disability Adjusted Life Years).The IHME, which has benefited from generous funding from the Gates Foundation, produces profuse metrics and estimates, calculations, and projections, which nowadays deeply shape the way health problems are being known, compared, and governed.Although the WHO initially attempted to equal the IHME as a provider of health metrics, the IHME has now reached a position of dominance in global health. The WHO itself now increasingly relies on those numbers for its own sense-making and agenda-setting exercises.Other “data” initiatives have since then further stabilised the strong presence of philanthropists in global health. In 2015, Bloomberg Philanthropies, for instance, launched its own Data for Health initiative, also co-funded with the Australian government and the Gates Foundation, to “strengthen and standardise birth and death records and to better inform policymaking and improve public health outcomes”.Vital Strategies, which describes itself as a global health non-profit organisation, entirely funded by Bloomberg Philanthropies, acts as the implementing partner of Data for Health. In that capacity, Vital Strategies supports the WHO in its risk monitoring work. As their resources often surpass those of the WHO, philanthropists’ data centers have come to sit at the core of global infrastructures of quantification, providing data and metrics to the WHO and supporting it in its own monitoring work.It is on the basis of those estimates that philanthropic organisations themselves and global health actors at large produce calculations to identify which health interventions could “save the most lives” and be most cost-effective. Interventions considered to be “best buys” and funding priorities have, thus, been identified on the basis of such metrics.Effects on global health governanceGBD results have highlighted that diseases like malaria, HIV, and later non-communicable diseases (NCDs) account for a massive “burden” of DALYS.Such numbers have helped, for instance, scale-up interventions for malaria and HIV treatment. The distribution of hundreds of millions of insecticide-treated nets has become a flagship intervention to solve malaria, with quantifiable impact, supported by the Gates Foundation but also global health actors at large. As philanthropic foundations increasingly partner with the WHO and other global health actors, they can, indeed, effectively translate this evidence in identifiable targets which all global health actors try to reach.While supporting such interventions is in itself laudable, what is questioning is that this calculative logic introduced a particular way of valuing health interventions, toward an approach in which ‘results’ must be continuously and quantitatively evidenced. This logic has favoured, first, a move toward population-based interventions, which alone can be shown to be producing significant and measurable results. This approach implies that problems are seen mainly in terms of their magnitude and that interventions need to have “scalability” and “reach population impact”. Such interventions enable funders to calculate impact and returns on investment in a standardised way.Second, this approach also favours highly technical interventions, rather than complex, structural interventions, as it is easier to produce evidence on their impact and the economic returns they generate.With regard to the treatment of high blood pressure, for instance, anti-hypertensive therapy has been privileged. While philanthropists and the WHO also promote interventions that target salt intake and trans-fat in food, these tend to be less central and fashioned by philanthropists as more complex, because population-based impact measurements are unavailable. The identification of hypertensive therapy as a most effective intervention was largely identified through the funding of modelling scenarios and projections by Bloomberg Philanthropies, which has largely invested in the field to find out which hypothetical interventions would bring the best returns.The involvement of philanthropists has therefore contributed to reinforcing a solutionist approach to health, where “quick fixes” are favoured, while factors relating to socioeconomic and environmental conditions problems are too often ignored.Understanding this shift is crucial. It reveals that as private resources are called in to fill existing funding gaps, such a move is not neutral but deeply political.Although the prevention of diseases is in itself a laudable objective for improving public health, what is interrogating is how the knowledge produced by these philanthropic actors, largely rooted in for-profit strategies and logics, is instrumental in making health conditions known, treated, and governed. A weekly e-mail in English featuring expertise from scholars and researchers. It provides an introduction to the diversity of research coming out of the continent and considers some of the key issues facing European countries. Get the newsletter!Annabelle Littoz-Monnet a reçu des financements du Fonds National Suisse de la recherche Scientifique (FNS).