Wednesday, October 19, 2016
By Jeff Mitchell, Head of School, Currey Ingram Academy, Brentwood, TN

In this FastStats SAIS and NAIS faculty salaries are compared.

Figure 1 shows the median salaries of SAIS and NAIS teachers for the past ten years. The graph shows a healthy upward trend for median salaries overall, and a steady gap between NAIS and SAIS schools, with NAIS teachers enjoying higher median salaries.

But Figure 1 only tells some of the story. Teacher load, for example, is worthy of mention. Simply put, teacher load refers to the median number of students a particular teacher teaches. Figure 2 shows the median teacher load for K-5 teachers in both the NAIS and the SAIS (see footnote before reading on). From Figure 2 it’s clear that SAIS K-5 teachers have a slightly higher median load of students.

Figure 3 shows data for 6-8 teachers. As we would expect, based on the development needs of the students, 6-8 teachers have higher median loads than K-5 teachers. Also noteworthy is that the gap between SAIS and NAIS teachers widens a little in these grades, with SAIS faculty teaching more students.

Figure 4 shows the same graph but for 9-12 teachers. Again, as educators we expect the median teacher load for the typical high school teacher to be higher than both the other division levels (see footnote before reading on). Contrary to Figure 1 and Figure 2, however, is that the median teacher load for NAIS teachers is now higher than for SAIS teachers.

This is an interesting variation in the data. How it is that SAIS schools have higher median teacher loads K-8 but not in grades 9-12 is puzzling. It’s possible that it could be related to enrollment numbers and patterns.

The median SAIS K-12 enrollment (575) is a substantially greater than the median NAIS enrollment (375). When breaking this down by Division, it’s clear that SAIS middle schools have a lot more students than NAIS middle schools. SAIS lower schools have more students than NAIS lower schools, but not to the same degree as for middle school. SAIS and NAIS upper school median enrollment are essentially the same.

From this, it could be argued that the higher teacher loads and class sizes in the SAIS middle school and lower schools are due to enrollment efficiency. That is, more classes are closer to their maximum enrollment in SAIS schools which would mean, on average, that SAIS teachers would have more students to teach (all other things being equal).

This, however, does not fully explain why the upper school data changed direction. One thought is that there are disproportionately more 9-12 only schools in the NAIS as a whole, versus the SAIS. If this is the case, these schools’ enrollment and financial models would be more sensitive to maximizing enrollment in the four grades offered, versus K-12 schools that can “subsidize” certain grades via enrollment in other grades.

In summary, SAIS K-8 teachers teach more students and are paid less, while SAIS 9-12 teachers are paid less but have smaller teaching loads.

Compensation also includes benefits. Although the data is not presented in this analysis, I know from previous FastStats analyses and my own research, that the median difference in the value of benefits for NAIS teachers versus SAIS teachers is at least as large as it is for salaries.

But that too is not the end of the story. Mentioned in the first footnote is that the teacher load variable used is a per class median. It’s conceivable, but doubtful, that the overall number of classes taught might vary between NAIS and SAIS teachers. If, for example, NAIS teachers taught more instructional minutes than SAIS teachers, it would certainly mitigate the differences found with median teacher load.

One consideration that likely sheds more light on SAIS teacher compensation versus their NAIS counterparts is regional difference in cost of living. Although very difficult to make broad-brush comparisons such as this, it is likely that that the cost of living for most SAIS teachers is less than most NAIS teachers. For example, assuming a 10 percent overall difference in cost of living washes much of the compensation discrepancies away.

The most useful application of this analysis is at your local (market) level. How does your school compare with local independent schools? How does your school compare with local public schools? For example, although matching-up with local public schools is often a challenge when it comes to outright salary and benefits (especially retirement and health insurance), a typically significant difference is seen when teacher load is taken into account. When both the number of students taught and the number of minutes taught are compared, independent teachers tend to fare favorably.

*The reader should note that this is the median load per class. To determine the total teacher load you would have to multiply by the number of classes taught. As a rough estimate, a lot of independent schools require full-time teachers to teach either four or five courses.

**At this time it is important to distinguish between teacher load and class size. In DASL, class size is the ratio of the overall number of teachers over the total number of students (within a division). Whereas, teacher load is the number of students a particular teacher teaches. Usually, class size is smaller number than teacher load.

Jeff Mitchell
Head of School
Currey Ingram Academy
Brentwood, TN