Methodology

WICHE’s methodology is based on data on births, enrollment numbers for grades one through 12 (foregoing kindergarten numbers due to volatility), and the numbers of graduates in each state. This information is used to calculate progression rates and project future years of enrollment and graduates. The projections of future enrollments and graduates are built on an assumption that trends and policy changes affecting enrollment — including immigration, mortality, retention, and progression — will continue. In the near term, this generally holds true, but like any model of the future, the farther out the forecast reaches, the greater the uncertainty inherent in the projections.

The strength of the WICHE model is that it captures many different factors — including immigration, mortality, stop-outs, and other events impacting enrollments and graduates — that impact future numbers without modeling them individually.

Due to data anomalies resulting from the pandemic, WICHE has made slight adjustments to the methodology to account for the 2020-21 school year, which showed dips in progression rates across most public school enrollments, measured by the rate at which students progress from one grade to the next. Those rates have generally rebounded to pre-pandemic levels in the two subsequent years of data analyzed, suggesting that this is a one-time impact. WICHE adjusted the weighting of its model to account for this, using an approach that produces results nearly identical to the traditional model without perpetuating what seems to be a one-time drop in public school progression rates. More detailed information on the approach is provided in the Technical Appendix.