Introduction: the cost of inaction on equity in health and its social determinants
The 2023 Global Economic Prospects report projected that global economic growth would be so weak that it would put the world economy at high risk of recession that year.1 As a result, countries have been more likely to face mounting financial stress that has threatened both government spending and aid budgets. At the same time, demands on the public purse are growing; countries face unprecedented, interlocking crises—an ongoing pandemic, rising geopolitical tensions and conflict, widespread food insecurity and the climate crisis, among others. Projections show that these crises will constrain health budgets—which, by 2027, will remain lower than prepandemic levels in 41 countries and only weakly increase in 69.2 These limitations will be exacerbated by the corresponding rise in debt and interest payments across low-income and lower-middle-income countries.2
Large-scale investments in health equity and its social determinants can help put our world economy back on track (box 1). The high returns on investment (ROIs) in health have long been demonstrated (table 1), with each year of life expectancy gained raising gross domestic product (GDP) per capita by approximately 4% through improvements in human capital (box 2) and reductions in downstream healthcare needs and expenditures.3 4 Since health is primarily driven by social determinants—which some studies estimate account for 70%–90% of modifiable factors in health outcomes, while health service delivery accounts for the remaining 10%–30%—so too are these associated economic returns.5 6 But even more impressive ROIs can be achieved if investments are directly linked to reducing health inequities.
Defining social determinants of health (SDH)
The WHO defines the SDH as: “the conditions in which people are born, grow, work, live, and age” and the systems shaping these conditions including “people’s access to power, money and resources”.16
The SDH include the following: early childhood development; education; food security; housing, basic amenities and environment; fair employment and decent work (including working life conditions); social protection and universal health coverage.16 They also include the commercial determinants of health, or “conditions, actions and omissions by corporate actors that affect health” (ie, access to tobacco, alcohol, unhealthy foods and many SDH including income, workplace safety, environmental degradation, working life conditions and access to healthcare).26
Structural discrimination underlies inequities in SDH, including discrimination by race, class, gender and sexuality, religion and disability, among others. Inequities in SDH, in turn, are the drivers of inequities in health—“unfair, avoidable, and remediable differences in health between social groups”.16
Defining human capital
As outlined by the World Bank, both human and physical capital are required for economic growth and development. Human capital is defined as “the knowledge, skills, and health that people accumulate throughout their lives, which enable them to become productive, members of society”.9 Therefore, human capital depends on education and health throughout the lifespan.
The Human Capital Index (HCI) is a measure that intends to capture the amount of human capital, or productive potential, a child born today could expect to attain by age 18.
Yet data show that gross domestic product (GDP) and HCI are not perfectly correlated, which suggests several key insights.9
First, national averages of HCI may obscure important human capital inequities across social groups within countries. For example, disaggregated analyses show that poor and rich households within a single country do not always benefit evenly from national gains in average human capital.9
Second, productive potential may not translate into actual productivity due to barriers to full employment. For example, in many countries, gender-based barriers to employment lead to significant gaps in how human capital is actually used across genders.9 It is likely that similar gaps, which reduce the return on investment (ROI) in human capital, exist across other discriminatory structures—including race or ethnicity, religion, and gender identity and sexual orientation, among others.
Third, inequities in human capital and how it is used may threaten the ROI in human capital (ie, investments in the education and health sectors) and therefore economic growth and development. The ROI forgone by these human capital gaps has not been quantified.
Unfortunately, there is clear evidence demonstrating that inequities both across and within countries have widened during the pandemic, increasing the imperative to act. For example, during COVID-19, income inequality between all countries and within emerging market and developing economies worsened, with larger projected impacts in the longer term.7
The case for improving social determinants of health (SDH) was emphatically made over 15 years ago,8 yet progress has been stymied by the complex and seemingly inertial political economy of SDH. While the concept of SDH has gained some traction within the health community, entrenched interests to preserve the status quo, which favours concentration and retention of power and resources in global and national elites over improving equity for all, remain fundamental barriers to progress. In the face of such challenges, champions of SDH are tasked with doubling down on efforts to strategically and coherently engage with the political elites who hold decision-making authority over SDH across countries—including Ministers of Finance. To this end, while insufficient on its own, a sharpened investment case for SDH is one key tool to engage political elites on the cost of inaction and ROIs in health equity, in quantitative, economic terms.