Guide to This Edition
This edition of Projections of Education Statistics to 2011 provides projections
for key education statistics, including enrollment, graduates, teachers,
and expenditures in elementary and secondary schools and enrollment
and graduates of degreegranting institutions. Currentfund expenditures
of degreegranting institutions are excluded from this edition because
of lack of available data for recent years. The tables, figures,
and text contain national data on enrollment, teachers, graduates,
and expenditures for the past 14 years and projections to the year
2011. The tables, figures, and text contain statelevel data on
projections of public school elementary and secondary enrollment
and public high school graduates to the year 2011. Similar methodologies
were used to obtain a uniform set of projections for 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 appearing
in this report. These projections reflect 1999 population estimates
and population projections based on the 1990 census, but are not
adjusted for the 1990 net undercount of 4 to 5 million. The population
projections are not based on the 2000 census data. Projections of
national population data are not scheduled for release until 2002.
Appendix A describes the methodology
and assumptions used to develop the projections. Appendix
B contains tables of supplementary data. Data sources are presented
in appendix C. Appendix
D is a glossary of terms. Appendix E
describes the survey methodology of the 1999 Integrated Postsecondary
Education Data System (Fall Enrollment).
Limitations of Projections
Projections of time series usually differ from the final reported
data due to errors from many sources. This is because of the inherent
nature of the statistical universe from which the basic data are
obtained and the properties of projection methodologies, which
depend on the validity of many assumptions. Therefore, alternative
projections are shown for most statistical series to denote the
uncertainty involved in making projections. These alternatives
are not statistical confidence limits, but instead represent judgments
made by the authors as to reasonable upper and lower bounds. The
mean absolute percentage error is one way to express the forecast
accuracy of past projections. This measure expresses the average
value of the absolute value of errors in percentage terms. For
example, the mean absolute percentage errors of public school
enrollment in grades K12 for lead times of 1, 2, 5, and 10 years
were 0.2, 0.5, 1.2, and 2.9 percent, respectively. On the other
hand, mean absolute percentage errors for doctor's degrees for
lead times of 1, 2, and 5 years were 2.0, 2.8, and 3.7 percent
respectively. For more information on mean absolute percentage
errors, see table A2.
Alternative projections are presented for enrollment in degreegranting
institutions, earned degrees conferred, elementary and secondary
teachers, and expenditures of public elementary and secondary
schools.
back to top
