IntroductionUnderstanding and alleviating inequality in opportunity is one of the most critical challenges currently facing policymakers in the United States (U.S.) and around the world1,2,3. Research across many academic fields consistently argues that life course inequality in educational attainment, health, labor market participation and earnings, happiness, and other measures of social wellbeing is shaped by disparate opportunities, resources, and human capital investments directed towards children4. The childhood resources that are needed to produce long-run outcomes are diverse and include: housing5, health care6, nutritional food7, preschool and other care environments8, high-quality education9, time parents and families spend reading to and playing with children10, after-school and enrichment activities11, access to public spaces like libraries12, and many others.Within each of these sectors and domains, existing scholarship indicates that children from lower socioeconomic backgrounds and racial/ethnic minorities tend to obtain fewer investments4. Differential investment, in turn, contributes to large gaps in educational achievement, economic mobility, health, and overall wellbeing13,14,15. For example, in the U.S., test-score gaps between children from the top and bottom quartiles (i.e., top versus bottom 25%) of household income and between black or Hispanic versus white children are estimated to be three-quarters of a standard deviation, if not larger14,16, equivalent to over a year of learning17. In young adulthood, income-based and race/ethnicity gaps persist in educational attainment and employment18, as well as in health and happiness19. Gaps in median lifetime earnings and life expectancy are similarly large across income quartiles and race/ethnicity groups20. At least in the U.S., gaps in educational outcomes and opportunity between females and males are substantially smaller, though gaps by sex are large for other metrics (e.g., earnings), as well as in other countries and contexts21,22.Despite longstanding interest in quantifying disparities in childhood human capital investments, the empirical literature remains piecemeal in nature. Much of the existing scholarship tends to focus on investments in one sector (e.g., education or health), setting (e.g., home, school, or community), or childhood stage23. More comprehensive assessments that aggregate information across sectors, settings, and ages tend to focus on public24,25 or private expenditures26 or nonmonetary investments such as parent and family time27,28. Each type of analysis, on its own, narrows the definition of childhood investment and thus leaves out a large share of the total resources directed toward children.The siloed nature of existing literature is misaligned with longstanding theory and consensus across academic disciplines that the investment mix is as important as any given investment. Studies using credible designs show that a range of goods—medical services, childhood nutrition, housing, early childhood education, teachers, and many others—all improve long-term outcomes4,24. Literature on the effectiveness of family-based investments that are produced mainly with parent and caregiver time is less developed, focusing more on the unequal distribution of time across children from different backgrounds27,28. However, theory and some empirical work suggests that structured family time in informal educational activities (e.g., reading, visiting a library) and in recreation activities (e.g., sports, projects, arts and crafts) produce cognitive (e.g., language acquisition) and socio-emotional skills (e.g., secure social attachments, perseverance)29,30. Unstructured time between children and caregivers that includes a high density of language can have similar effects31,32,33,34,35, which in our data include activities, such as discussion of heritage and meal and transportation time. Notably, while levels of parent and family time differ by household income and race/ethnicity, existing literature suggests that their effects on child outcomes do not36,37.Further, economists, developmental psychologists, and sociologists all argue that all of these resources are needed to produce long-term outcomes, that resources interact with each other, and that the timing of investment relative to developmental stage is critical13,38,39,40,41. Thus, the siloed character of existing work that attempts to quantify investment disparities has limited our ability to understand disparities in the total investment mix that theory predicts is important4,42,43,44.We produce estimates of the quantity of childhood investments that U.S. children receive between birth and age 18, by household income, race/ethnicity, and sex, and at what specific ages children receive them. Our primary contribution is our comprehensiveness. We compile and analyze data from 10 federally sponsored and nationally representative surveys, spanning 2010–2023 (see Supplementary Methods Tables 1 and 2 for details on the data). We examine investment levels across six sectors and 10 domains (with some sectors including multiple domains): child care, clothing, education (i.e., formal education, informal educational experiences, and college preparation), health (i.e., health care, nutrition, and exercise), housing, and transportation. In total, we include 77 highly granular individual investments from out-patient versus emergency medical visits, whole fruit versus fruit juice, and compulsory education services (e.g., teachers) versus compensatory ones (e.g., special education, tutoring) meant to remediate academic progress (Table 1).Table 1 Summary of investments included in 10 nationally representative surveysFull size tableTable 2 Investments by childhood stage (2024 dollars)Full size tableWe track activities that families purchase or are provided via public subsidy and those that they produce with caregiver time, all captured in dollar units that are straightforward to aggregate and easily interpreted. Broadly, our “ingredients method” starts by identifying and specifying the ingredients (e.g., personnel, materials, and fees) for a given investment, then prices each ingredient, and sums across ingredients (for details, see Supplementary Data and Supplementary Methods Table 3)45,46,47. In addition to providing a method to combine monetary and nonmonetary investments, our ingredients approach allows us to compare children who receive similar investments but at different market prices (e.g., food purchased in a grocery store versus restaurant), and to compare children who receive similar investment totals but with different inputs (e.g., caregiver time versus market expenditures). An exception is clothing, where we only can track family expenditures without adjusting for market prices, which we still include given its centrality in related analyses26.Table 3 Childhood investments by type of investment and costing approachFull size tableIn this study, we show that the average total investment per child from birth to age 18 in the U.S. is $502,152 (in 2024 USD). Income-based and racial/ethnic disparities in the total investment, which range from 6% to 15%, are smaller than some previous studies indicate26. However, the relative homogeneity in total investments across the childhood lifecycle masks two important patterns: (1) a differential mix of expenditures versus unpaid caregiver time; and (2) substantial disparities from birth to age five that converge at later ages due to the universal nature of public education and differential levels of compensatory spending at older ages (e.g., special education). Finally, we show that the mix of public and privately financed investments vary across groups and that investment disparities are largest in sectors with relatively low levels of public support (e.g., housing, child care). While our results are purely descriptive, the variation in the public-private mix that we observe is consistent with public investments serving an equalizing role.ResultsTotal investments in children and youthWe begin by describing the total investment mix, averaging across all children. Table 1 shows that the average total investment from birth to age 18 is $502,152 (in 2024 USD). Informal educational experiences represent the largest domain (23%), followed by nutrition (22%), housing (16%), and formal education (15%). Each of the remaining six domains (health care, exercise, clothing, child care, transportation, and college preparation) individually represent less than 10% of the total. While informal educational experiences, transportation, and exercise are primarily or exclusively comprised of activities where the primary ingredient is parent and family member time, housing, formal education, health care, child care, college preparation, and clothing are primarily or exclusively expenditure based. Nutrition is more mixed, including investments in caloric intake from specific foods and the large amount of time that parents and families spend with children during meals.Figure 1, panel A, documents these trends visually, while panels B and C show age gradients in how investments are allocated between birth and age 18 (for expenditure- and parent and family time-focused investments, respectively). In the first year of life, time spent on feeding (i.e., breastfeeding, formula feeding, other meals) is the single largest investment, just shy of $20,000 and roughly equivalent to 1.8 h of parent or family time per day. By age one, parent and family time-focused investments in meals levels out and decreases as children grow, while expenditure-focused investments in food increase slightly over the childhood years. Like nutrition, health care investments are higher in the first year of life, which includes costs associated with birth and frequent doctor visits. Clothing expenditures track very closely with investments in food and health care. Housing is a large investment across all childhood years, with a slight increase over time driven by a reduction in shared rooms as children age.Fig. 1: Investments in children, by domain, type, and age.Full size imagea Documents the mean total investment between birth and age 18, by domain and type of investment (i.e., expenditure- versus parent and family time-focused investments). Dollar units are on the left y-axis, and percent of total investment (summing across all domains) is on the right y-axis. b, c Disaggregate means by investment type and age. Child care, clothing, college preparation, and housing only include expenditure-based investments. Transportation only includes time-based investments. In b, c, 95% confidence intervals (CI) for the means are included. N = 1,202,932 in the full sample.Informal educational experiences begin at birth—and increase substantially at age one—with early literacy (e.g., reading, telling stories, and singing to children), arts and crafts, and other activities. The peak exactly at age five is somewhat of a data artifact, reflecting how roughly two-thirds of 5-year-olds in our data start kindergarten while others wait a year. As a result, some 5-year-olds receive home-based informal educational experiences from parents and families only captured in the data through age five (e.g., early literacy activities) in addition to other time- and expenditure-focused informal educational activities only captured starting at age five (e.g., projects, lessons, help with homework) (see Supplementary Data). Both exercise (e.g., time at parks/playing sports) and child care also start relatively high at birth and then decline at age five with the start of formal school. Our data include three types of child care, all of which are provided by someone other than a parent: center-based care, home-based care from a nonrelative (e.g., nanny), and home-based relative care, most often provided by grandparents. In our primary analyses, we exclude relative care because it is likely duplicative with informal educational experiences facilitated by family members. For formal education, investments can start at birth with special education services. From kindergarten through 12th grade, the slight decrease over time is driven primarily by larger class sizes in middle and high school, which reduce per-child personnel costs. Time spent transporting children (often to/from school) is a much smaller but steady investment over time, while college preparation is a small, one-time investment that we plot at age 16 (but could occur at any time in high school).In the discussion, we describe how our calculations likely underestimate the total investment in children and youth, given some investments that we cannot capture reliably in our data (e.g., facilities, supplementary teachers). However, the primary contribution of our analyses in disparities in investments reduces the importance of underestimating the overall level.Disparities in the total investmentWe describe differences in investments by household income, race/ethnicity, and sex. Income is measured at the household level, and we group children by quartiles. Race/ethnicity is self- or guardian-reported using survey questions that ask about race and Hispanic origin in separate questions. We combine these questions to form categories for non-Hispanic Asian American and Pacific Islander, non-Hispanic black, non-Hispanic white (henceforth “AAPI”, “black”, and “white”, respectively), and Hispanic. Sample sizes for American Indian/Alaska Natives, other races, and children identifying with multiple races are too small to generate statistically reliable results, and their exclusion remains a limitation of our study. Sex (male/female) is based on self- or guardian-reported survey questions that ask about sex assigned at birth.Table 2, panel A describes disparities in total investment amounts. Relative to children in the top quartile of household income, whose total investment is $557,382, children in the bottom quartile receive investments that are roughly $86,000 less (z = 23.81, p