# Projections of Education Statistics to 2030

## Projections

This edition of *Projections of Education Statistics *provides projections for key education statistics,
including enrollment, graduates, teachers, and expenditures in elementary and secondary public and private schools, as
well as enrollment and degrees conferred at degree-granting postsecondary institutions. Included are national data on
enrollment and graduates since at least 2010 and projections to the year 2030. This historical period (roughly 10
years prior to the latest historical data) was chosen to highlight recent trends, but longer trends are available in
select reference tables.** **Also included are state-level data on enrollment in public elementary and
secondary schools over the same period. This report is organized by the level of schooling with sections 1, 2, 3, and
4 covering aspects of elementary and secondary education and sections 5 and 6 covering aspects of postsecondary
education.

There are a number of limitations in projecting some statistics. Because of this, state-level data on enrollment and graduates in private elementary and secondary schools and on enrollment and degrees conferred in degree- granting postsecondary institutions are not included. Neither the actual numbers nor the projections of public and private elementary and secondary school enrollment include homeschooled students. While there were enough years of data to produce projections of public elementary and secondary enrollment separately for Asians and Pacific Islanders, there were not enough years of data to produce separate projections for Asians and Pacific Islanders for either public high school graduates or enrollment in degree-granting postsecondary institutions.

Similar methodologies were used to obtain a uniform set of projections for each of the 50 states and the District of Columbia. These projections are further adjusted to agree with the national projections of public elementary and secondary school enrollment and public high school graduates contained in this report.

The summary of projections provides highlights of the national and state data, while the reference tables (in the
*Digest of Education Statistics 2021*) and figures present more detail. All calculations within *Projections
of Education Statistics *are based on unrounded estimates. Therefore, the reader may find that a calculation,
such as a difference or percentage change, cited in the text or figure may not be identical to the calculation
obtained by using the rounded values shown in the accompanying tables. Most figures in this report present historical
and forecasted data from 2010 through 2030. The shaded area of these figures highlights the projected data and begins
at the last year of actual data and ends in 2030. As the last year of historical data differs by survey, the year in
which the shaded area begins also differs.

Most statements in sections 1 through 6 examine a single statistic over a period of time. In each case, a trend test
using linear regression was conducted to test for structure in the data over that time period. If the *p *value
for the trend variable was significant at less than or equal to .05, the text states that the statistic has either
“increased” or “decreased” (i.e., there was a measurable trend). If the *p *value was
greater than .05 and the data for both the first and last years of the time period come from a universe sample and/or
are projections, then the text compares the first and last years in the time period, describing them as
“higher” or “lower”. However, if the data for at least one of the two years came from a sample
survey, a two-tailed *t *test at the .05 level was conducted to determine if any apparent difference
between the data for the two years is not reliably measurable due to the uncertainty around the data. Depending on the
results of the test, the text will either include a comparison of the two numbers or say that there was no measurable
difference between the two numbers.

Appendix A describes the methodology and assumptions used to develop the projections; appendix B presents supplementary tables; appendix C describes data sources; appendix D is a list of the references; appendix E presents a list of abbreviations; and appendix F is a glossary of terms.

## Limitations of Projections

In this edition, projections are complicated by the onset of the coronavirus pandemic in 2020. Projections are based
on the assumption that historical patterns will continue into the future. This presents challenges both for (1) using
*pre*pandemic historical data to predict unprecedented pandemic-era behaviors, and (2) using pandemic-era data
to predict *post*pandemic behaviors. This edition of the *Projections of Education Statistics *includes
both scenarios. At the time these forecasts were produced, the latest historical data for public elementary and
secondary enrollments were from fall 2020 (during the pandemic), while the latest historical data for other outcomes
were from fall 2019 or earlier (prepandemic). All data presented in this report were first published in the *Digest of Education Statistics 2021*. By
the time of this report publication, new historical data will be available for all of the education statistics
presented below. These new historical data represent an additional year of education during the pandemic, which will
be incorporated into the forthcoming *Projections of Education Statistics to 2031*.

Even without a pandemic, projections of a time series usually differ from the final reported data due to errors from many sources, such as the properties of the projection methodologies, which depend on the validity of many assumptions.

The mean absolute percentage error is one way to express the forecast accuracy of past projections. This measure
expresses the average of the absolute values of errors in percentage terms, where errors are the differences between
past projections and actual data. For example, based on past editions of *Projections of Education Statistics*,
the mean absolute percentage errors of public school enrollment in grades prekindergarten through 12 for lead times of
1, 2, 5, and 10 years were 0.3, 0.5, 1.1, and 2.5 percent, respectively. In contrast, mean absolute percentage errors of
private school enrollment in grades prekindergarten through 8 for lead times of 1, 2, 5, and 10 years were 3.9, 5.6,
8.0, and 19.2 percent, respectively. For more information on mean absolute percentage errors, see table A-2 in appendix A.