National Center for Education Statistics

Challenges, changes, and current practices for measuring student socioeconomic status

By Lauren Musu-Gillette

There is an abundance of data and research that shows a relationship between a student’s socioeconomic status (SES) and their academic outcomes. For example, students from low-SES families are far more likely to drop out and far less likely to complete a bachelor’s degree than their peers from middle- and high-SES families.

As we seek to better interpret and understand these and other findings related to student progress, it important for NCES to try to collect accurate and complete measures of student SES.

Percentage distribution of highest level of educational attainment of spring 2002 high school sophomores in 2012, by socioeconomic status (SES)

SOURCE: U.S. Department of Education, National Center for Education Statistics, Education Longitudinal Study of 2002 (ELS:2002), Base Year and Third Follow-up. See Digest of Education Statistics 2014, table 104.91.

Measures of SES usually combine several different statistics, most commonly family income/wealth, parent educational attainment, and parent occupation.[1] In some surveys, NCES is able to collect data directly from parents in order to measure all these component of SES. However, in many assessments and some surveys, NCES is unable to collect this information directly from parents making it difficult to create a consistent measure of SES across the Center.

NCES staff recognizes both the importance of collecting valid and reliable SES data, and the challenges associated with doing so. For example, between 2010 and 2012, NCES convened a panel of experts in the fields of economics, education, statistics, human development, and sociology who provided information on SES, including theoretical foundations, common components, data collection and measurement approaches, and possible implications of a new measure of SES for the National Assessment of Educational Progress (NAEP). There are several challenges for NAEP when considering the inclusion of survey items that can be used to measure student SES. Since NAEP does not include a parent survey, student or school-level data is currently the only potential source for data. However, data on SES can be difficult to collect directly from students as many are unable to accurately respond to questions about their family income or the highest level of their parent or parents’ education.

In terms of school-level data, student eligibility for free and reduced price meals has historically been an important indicator of household income. However, recent changes in the way schools are required to record eligibility for free and reduced price meals has required researchers to reconsider the use of this data point  as a measure of family income, or as a proxy, more generally, for SES. A recent NAEP blog on this topic provides additional information on NAEP-specific considerations, but these changes impact data collection efforts across the agency. Additionally, the free and reduced price meals data only reflect income, which is only part of a complete SES measure, and does not differentiate between middle and high SES students.

Given these changes, NCES is working to  identify other variables that could serve as more reliable and valid measures of student SES.  For example, several NCES staff members are involved with the Alternative SES Measure Working Group as part of the National Forum on Education Statistics. This group recently released the Forum Guide to Alternative Measures of Socioeconomic Status in Education Data Systems. This publication presents advantages and disadvantages for eight alternative measures of SES.  These resources are intended to serve as reference tools for education agencies engaged in identifying, evaluating, or implementing alternative SES measures. They are not data collection instruments and do not represent federal reporting requirements.

Collecting data on and examining differences in educational outcomes by student SES is important to both researchers and educators. As data systems evolve and measures of SES change over time, NCES is committed to researching and collecting the best data possible with the resources available.


[1] For most NCES surveys, parent educational attainment and parent occupation is based on the highest level achieved by either parent and/or guardian in the household.

Free or reduced price lunch: A proxy for poverty?

By Tom Snyder and Lauren Musu-Gillette

The percentage of students receiving free or reduced price lunch is often used as a proxy measure for the percentage of students living in poverty. While the percentage of students receiving free or reduced price lunch can provide some information about relative poverty, it should not be confused with the actual percentage of students in poverty enrolled in school. In 2012, just over half of public school children were eligible for free/reduced price lunches. In contrast, the actual poverty rate of public school students was 22 percent. Despite the correlation between the two measures, it is important to understand that they differ in important ways and that the difference is growing.

As the largest federal program for elementary and secondary schools, the National School Lunch Program provided meals to more than 31 million children each school day in 2012. All lunches provided by the National School Lunch Program are considered subsidized to some extent because meal-service programs at schools must operate as non-profit programs. While all students at participating schools are eligible for regular priced lunches through the National School Lunch Program, there are multiple ways in which a child can become eligible for a free/reduced price lunch. Traditionally, family income has been used to establish eligibility for free/reduced price lunch.  

One way the percentage of students in poverty and those eligible for free/reduced price lunch differ is that many students eligible for free/reduced price lunch fall above the federal poverty threshold. A student from a household with an income at or below 130 percent of the poverty income threshold is eligible for free lunch. A student from a household with an income between 130 percent and up to 185 percent of the poverty threshold is eligible for reduced price lunch.

In addition, some groups of children such as foster children, children participating in Head Start and Migrant Education Programs, or children receiving services under the Runaway and Homeless Youth Act are eligible for free/reduced price lunch. Also, under the Community Eligibility option, some non-poor children may be included in the program if their district decides that it would be more efficient from an administrative or service delivery perspective to provide the free lunches to all children in the school. Thus, the percentage of students receiving free or reduced price lunch includes all students at or below 185 percent of the poverty threshold, plus some additional non-poor children who meet other eligibility criteria, plus other students in schools and districts that have exercised the Community Eligibility option, which results in a percentage that is more than double the official poverty rate.

Despite its limitations, the free/reduced price lunch data are frequently used by education researchers as a proxy for school poverty since this count is generally available at the school level, while the poverty rate is typically not available. Because the free/reduced price lunch eligibility is derived from the federal poverty level, and therefore highly related to it, the free/reduced price lunch percentage is useful to researchers from an analytic perspective.

In reports such as the Condition of Education, NCES has characterized a school as a high poverty school when more than 75 percent of its students are eligible for a free/reduced price lunch. In 2012-13, about 24 percent of students attended public schools that were classified as high poverty. Using this high poverty definition enables us to identify important differences among students: 45 percent of Black and Hispanic students attended such high poverty schools compared to 8 percent of White students.

Percentage of public school students in low-poverty and high-poverty schools, by race/ethnicity: School year 2012-13

This chart presents bars on the percentage of children attending low poverty and high poverty schools by race/ethnicity in school year 2012-13. The bars are in two groups, one group is for low poverty schools and the other group is for high poverty schools. The first group of bars show that 21 percent of total children, 29 percent of White children, 7 percent of Black children, 8 percent of Hispanic children, 38 percent of Asian children, 12 percent of Pacific Islander children, 8 percent of American Indian/Alaska Native children, and 22 percent of children of two or more races were in low-poverty schools in 2012-13. The second group of bars show that 24 percent of total children, 8 percent of White children, 45 percent of Black children, 45 percent of Hispanic children, 16 percent of Asian children, 26 percent of Pacific Islander children, 36 percent of American Indian/Alaska Native children, and 17 percent of children of two or more races were in high-poverty schools in 2012-13.

NOTE: High-poverty schools are defined as public schools where more than 75.0 percent of the students are eligible for free or reduced-price lunch (FRPL), and low-poverty schools are defined as public schools where 25.0 percent or less of the students are eligible for FRPL. 

SOURCE: U.S. Department of Education, National Center for Education Statistics, Common Core of Data (CCD), "Public Elementary/Secondary School Universe Sturvey," 2012-13. 

One of the important limitations of the free/reduced lunch count is that the change in the eligibility requirements under the Community Eligibility option has meant that more children are qualifying for free/reduced price lunches.  Between 2000-01 and 2012-13, the percentage of children eligible for a free/reduced price lunch increased from 38 percent to 50 percent, an increase of 12 percentage points. In contrast, the percentage of public school children who lived in poverty increased from 17 to 23 percent, an increase of 6 percentage points.

While the free/reduced lunch percentages can serve as a useful indicator of the relative numbers of poor children, it does not substitute as a measure of the level of child poverty, nor of changes in poverty rates over time. It is also important to keep in mind that neither free/reduced price lunch eligibility nor poverty should be considered measures of socioeconomic status (SES), which measures a broader spectrum of family characteristics (e.g. parental education and occupations) that may be related to student performance. Some NCES surveys already collect SES data while others are investigating options for collecting better indicators of students’ SES. These efforts will be detailed in a future blog post.

For more information on recent changes to free/reduced price lunch eligibility data in EDFacts see Free and Reduced-Price Lunch Eligibility Data in EDFacts: A White Paper on Current Status and Potential Changes