Quality schools, parks and playgrounds, clean air, access to healthy food, health care and safe housing—these are some of the conditions and resources children need to grow up healthy and become productive adults. Many children in the U.S. live in neighborhoods that provide access to these conditions—neighborhoods we describe as “high opportunity.” But many live in “low opportunity” neighborhoods with few or none of these conditions. Black, Hispanic and Native American children are especially likely to live in very low-opportunity neighborhoods. The Child Opportunity Index is a tool that describes and quantifies the neighborhood conditions U.S. children experience today, ranking them from lowest to highest opportunity.
See below for short definitions of the main Child Opportunity Index measures. Use the links on the right to read more complete definitions, or see the COI Technical Document for a detailed explanation of our methodology.
Child Opportunity Index
An index of neighborhood resources and conditions that help children develop in a healthy way. It combines data from 29 neighborhood-level indicators into a single composite measure.
Main features of the Child Opportunity Index 2.0:
- First single, consistent metric of contemporary child neighborhood opportunity
- Complete national coverage: provides data for nearly all U.S. neighborhoods (about 72,000 census tracts)
- Comprehensive: includes 29 indicators across three opportunity domains: education, health and environment, social and economic
- Longitudinal: available for 2010 and 2015, allowing comparisons over time
Child Opportunity Score
A single metric (from 1 to 100) that ranks all 72,000 neighborhoods in the U.S. according to their child opportunity. Child Opportunity Scores are also available for metros to assess their overall level of opportunity, and by race and ethnicity.
Child Opportunity Gap
The difference in neighborhood conditions (in Child Opportunity Score) between very high-opportunity neighborhoods and very low-opportunity neighborhoods in any given metro area.
Opportunity hoarding
We describe metro areas as hoarding opportunity when their Child Opportunity Gap is wider than average. In these areas, very low-opportunity neighborhoods have much worse conditions than very-high opportunity ones.
Opportunity sharing
We describe metro areas as sharing opportunity when the Child Opportunity Gap is narrower than average. In these areas the difference in conditions between very low-opportunity and very high-opportunity neighborhoods is much smaller.
Racial and Ethnic Opportunity Gap
The difference in neighborhood opportunity experienced by the typical child of a given racial/ethnic group and that experienced by the typical child of another racial/ethnic group—measured by the difference in Child Opportunity Scores between the two racial/ethnic groups.
The Child Opportunity Index (COI) 2.0 is an index of neighborhood features that help children develop in a healthy way. It combines data from 29 neighborhood-level indicators into a single composite measure that is available for nearly all U.S. neighborhoods (about 72,000 census tracts) for 2010 and 2015.
The 29 indicators cover three domains: education, health and environment and social and economic. Indicators in the education domain reflect quality and access to early childhood education, quality of elementary and secondary schools and social resources related to educational achievement. The health and environment domain reflects features of healthy environments, such as access to healthy food and green space, and features that are toxic, such as pollution from industry and exposure to extreme heat. The social and economic domain contains nine indicators measuring access to employment and neighborhood social and economic resources. All indicators are measured at the census tract level, which corresponds to the Census Bureau’s definition of neighborhoods.
We convert each indicator to z-scores, a common statistical procedure that puts indicators measured on different scales (e.g., counts, percentages, dollars) onto a common scale that is comparable across indicators, neighborhoods and over time. We then take a weighted average of the indicator z-scores within a domain to obtain a domain average z-score. Next, we take a weighted average of the averaged domain z-scores to create an overall index z-score that combines all indicators into a single measure, the Child Opportunity Index. The weights used in each step are calculated to reflect how strongly a given indicator or domain z-score predicts four different census tract-level outcomes: two indicators of intergenerational economic mobility taken from the Opportunity Atlas 1 and two health indicators taken from the 500 Cities health indicator database. 2 ;3
Based on the domain scores and the overall score, we create two neighborhood level measures that allow us to compare opportunity across neighborhoods and over time in an intuitive way: Child Opportunity Scores and Child Opportunity Levels.
- 1Chetty, R., Friedman, J. N., Hendren, N., Jones, M. R., & Porter, S. R. (2018). The Opportunity Atlas: Mapping the childhood roots of social mobility. Retrieved from website: https://ideas.repec.org/p/cen/wpaper/18-42.html.
- 2Centers for Disease Control and Prevention. (2017). 500 Cities Project: Local data for better health. Retrieved from website: https://www.cdc.gov/500cities/index.htm.
- 3Zhang, X., Holt, J. B., Lu, H., Wheaton, A. G., Ford, E. S., Greenlund, K. J., & Croft, J. B. (2014). Multilevel regression and poststratification for small-area estimation of population health outcomes: A case study of chronic obstructive pulmonary disease prevalence using the Behavioral Risk Factor Surveillance System. American Journal of Epidemiology, 179(8), 1025-1033. doi:10.1093/aje/kwu018.
Child Opportunity Scores can be used to compare neighborhood opportunity on a scale from 1 (lowest) to 100 (highest). To construct Child Opportunity Scores, we rank all neighborhoods nationally in terms of the overall Child Opportunity Index z-scores from lowest to highest and divide the neighborhoods into 100 rank-ordered groups. Each of the groups contains 1% of the child population and is assigned a Child Opportunity Score, from 1 to 100. The 1% of children living in the very lowest ranked neighborhoods (with a score of 1) face some of the worst neighborhood conditions in the U.S. The 1% of children living in the highest opportunity neighborhoods (with a score of 100) experiences some of the best conditions available to children. We use percentiles, weighted using the total number of children in a given tract, to exactly define the cut points dividing neighborhoods into groups that contain 1% of the child population each.
For some analysis, neighborhood-level Child Opportunity Scores are aggregated to reflect neighborhood opportunity experienced by the typical (median) child in a given metro area. We calculate aggregate opportunity scores for individual metros by taking the median value of scores across all tracts in the metro of interest, using the total number of children in each tract as weights.
In addition, we present aggregate racial/ethnic opportunity scores that reflect the neighborhood opportunity experienced by the typical child of each major racial/ethnic group in a given metro, using the total number of children of that racial/ethnic group in each tract as weights.
We also calculate aggregate Child Opportunity Scores for the 100 largest metros combined, by taking the median value of scores across all tracts in the 100 largest metros, using the total number of children in each tract as weights.
Child Opportunity Levels are five categories of neighborhood opportunity ranging from very low- to very high-opportunity. Child Opportunity Levels are constructed in much the same way as Child Opportunity Scores. We first rank neighborhoods and then divide them into ordered categories. In this case, we divide neighborhoods into five groups, each containing 20% of the child population. To facilitate interpretation, we label these groups as very low-, low-, moderate-, high- and very high-opportunity neighborhoods. We again use percentiles, weighted using the total number of children in a given tract, to exactly define the cut points dividing neighborhoods into groups that contain 20% of the child population each.
Both Child Opportunity Scores and Levels are relative measures of opportunity, i.e., the score or level assigned to a neighborhood depends on the set of neighborhoods to which it is being compared. When we create a Child Opportunity Score or level for a neighborhood based on its rank relative to all other neighborhoods in the U.S., we refer to that score or level as being “nationally normed.” For example, nationally normed Child Opportunity Levels are constructed by ranking all neighborhoods nationwide and dividing them into five groups containing 20% of the child population each. In contrast, metro normed Child Opportunity Levels are constructed by ranking all neighborhoods in a given metro and dividing them into five groups containing 20% of the metro area’s child population each. Nationally and metro normed scores are different but strongly correlated. Nationally and metro normed levels are often the same and are very highly correlated in most places.
Depending on the focus of the analysis, we sometimes present nationally normed Child Opportunity Levels and sometimes present metro normed Child Opportunity Levels. When we report results for the 100 largest metro areas combined, we use nationally normed levels. When we report results for individual metros in the context of a national story, we also use nationally normed levels. However, we generally use metro normed levels when we report results for individual metro areas.
The Child Opportunity Gap measures how far apart neighborhoods are in terms of opportunity for children living in very low- and very high-opportunity neighborhoods in each metro area. To quantify how unequal metro areas are in terms of neighborhood opportunity for children, we calculate the Child Opportunity Gap for each of the 100 largest metro areas. Specifically, we compare two groups of neighborhoods in each metro area, those with very low- and those with very high-opportunity, using metro normed Child Opportunity Levels to define each group. We then calculate the median opportunity scores for each of these two groups using nationally normed opportunity scores, weighted by the total number of children in each tract.
The Child Opportunity Gap for a metro area is the difference between the median opportunity score of its very high-opportunity neighborhood and the median score of its very low-opportunity neighborhood. We calculate a similar measure for the 100 largest metro areas combined, using the nationally normed Child Opportunity Levels to define the very low- and very high-opportunity scores.
Racial/ethnic opportunity gaps reflect the extent to which the neighborhood opportunity of a typical child of a specified race/ethnicity differs from the neighborhood opportunity of a typical child of another race/ethnicity in the same metro area.
We first calculate the opportunity score (nationally normed) for the neighborhood of the typical (median) child of a given racial/ethnicity in a given metro, weighting the score by the number of children of the specified racial/ethnic group in each neighborhood within the metro. We replicate this process to obtain the opportunity score for the neighborhood of the typical white child within the same metro. We then calculate the difference between the median opportunity score for white children and the median opportunity scores for children of other racial/ethnic groups. These differences are the racial/ethnic opportunity gaps. We also present racial/ethnic opportunity gaps for the 100 largest metros combined by comparing the weighted median opportunity scores of children of specified race/ethnicity with the scores of white children living in the 100 largest metros as a whole.