Methodology

PURPOSE

The purpose of this product is to compare starting teacher salaries and per-pupil revenues in each state to cost-adjusted salary and revenue figures that make dollar amounts comparable across the country by accounting for variation in living costs in different regions.

DATA

Sources:
Average starting teacher salaries in each state come from the National Education Association (NEA)
School district-level, 2013 finance data from the Census f33 data
County-level cost-of-living index data from the Council for Community and Economic Research
State- and national-level median household income from the Census, Small Area Income & Poverty Estimates (SAIPE)
School district-level, enrollment characteristics [number enrolled, FRL, IEP, LEP] from NCES, Elementary/Secondary Information System (ELSi)
School district-level student poverty estimates from SAIPE

Data exclusion criteria for per–pupil revenue analysis:
District-level school finance data was used as the basis of the district-level data set. Other data sources were merged onto this dataset with unmatched entries from the additional data sets being dropped such that every row in the data has school finance data
Starting with the full sample of 14,462 school districts in the school finance data set, the following exclusions were made:

1. Finance data missing an NCESID
2. Charter districts or districts where charter classification is missing [most of the districts with missing data seem to be ones we would want to exclude anyway, e.g. “computer association” districts, “interlocal cooperatives” etc.]
3. Special education, technical and vocational districts [excluded by finding districts that some form of special, technical or vocational in their name, with exceptions made for districts that appear to be more general districts]
4. Districts with ten or fewer students
5. Districts that enroll a proportion of IEP students that is more than two standard deviations (sd=.05) above the mean of 0.14
6. Districts missing cost-adjusting values
7. Districts with state+local revenues below $500

In total, 1,542 districts (11%) were excluded leaving 12,920 districts in the Power In Numbers sample

METHODS

Unadjusted spending at the state-level
District-level, per-pupil revenues were aggregated up to the state level using weighted means to adjust for the size of students enrollments within a district.

Revenues categorized as "Capital outlay and debt service programs" and "Sale of property" were subtracted from state and local revenues, respectively. These revenue streams can contribute to large fluctuations in district revenues from year to year and were excluded to minimize bias in our revenue calculations.

By weighting for enrollment, the state averages represent the average amount of revenue received by a student in the state (as opposed to the average amount of revenue a district in the state receives per student, which would be identified with an unweighted mean).

Adjusted spending at the state-level
In order to convert per-pupil revenues into figures that account for variation in the purchasing power of a dollar across different regions, we applied a cost-adjusting conversion from the Council for Community and Economic Research (C2ER) to each districts' revenues.

To adjust spending at the school district level, district revenues were adjusted using the C2ER county-level, cost-adjusting rate of the county identified by NCES as being associated with a district.

Similar to the unadjusted spending above, district-level, cost-adjusted, per-pupil revenues were aggregated up to the state level using weighted means to adjust for the size of students enrollments within a district.

Adjusted average teacher salaries at the state-level
In order to apply a comparable adjustment procedure to all of our analyses, we computed a state-level cost-adjustment rate by comparing the nominal and adjusted state-level revenue figures described above. This adjustment index for each state was then applied to the state-level, average starting teacher salary figures provided by NEA to produce cost-adjusted salary estimates.