Family Mobility and Christian School Retention: How Many Will Move Away?

Administrators understand the importance, not only of enrolling new students, but even more importantly, keeping those who are currently enrolled. It’s far easier to re-enroll a current child than it is to find, educate, and enroll a new family. Experientially, CSM has identified some useful metrics for retention. Above 90% is very good and shows the parent community is largely content. Remember that 5% of the population is dissatisfied at any given moment! Thus, everything above 95% re-enrollment is truly excellent – hard to attain, and even harder to sustain. On the other hand, anything routinely below 85% spells trouble for the long-term viability of a school. There are times when re-enrollment can take a drastic hit due to a factory closure or other external event, and that can lead to a one-time drop. However, any school that year after year is seeking to replace 15% of its students must carefully evaluate themselves to understand why. This kind of loss is simply not sustainable over the long haul. 

Calculating the retention rate is straightforward. Take the past year’s enrollment number and subtract the graduating class. Also subtract any families that have moved out of the school’s catchment area. Then divide this total by the number of students that has re-enrolled for the current year. This should be recorded and tracked year after year to find the trends. The same process should be followed for each grade. For example, how many of the current year’s third grade students enrolled into fourth grade. Doing this for every grade and classroom over time will uncover trends that would provoke questions about quality of instruction at a given level.  

Can we predict the number of families that will move out of our school’s catchment area? 

It would be helpful to put a ‘number’ into our budget calculations that reflected mobility as well as one that reflected the retention trend. Individual and household mobility is a phenomena that the Census Bureau regularly monitors and reports. 

The Census Bureau parses the data in dozens of ways, including gender, age, income, race, individuals, households, households with and without children, and households with children ages 6-17. It is this latter group that we consider here. When we worry about student numbers for next year, that concern is justified. From our schools’ point of view, the reality that movers are 9% of the population is sobering. While our retention rate might be 93%, up to an additional 9% of our families might be moving.  

This is mitigated somewhat by the fact that families with children move less than the general population. Households with children ages 6-17 are less likely to move in a given year, about 7.5%. We can infer typical reasons for this: 

• Families are more stable than individuals and less prone to impulse and/or risk.
• Parents want stability for their children and will even move into an area to be at a particular Christian school.
• Parents will typically not move once the child is in high school – protecting the middle and elementary age child in a multi-child family.

The numbers improve more once we consider where a family is moving to. Often families move to a new home but continue to keep their kids enrolled. To protect their children’s education, families will change jobs, change homes, and even change churches before they leave a school they love. The Census Bureau tracks whether the householder moves to a new country, a new state, or a new county, and they break that down by region. To refine the mover number, we will use leaving the county as a proxy for the likelihood that a move will mean a change of schools. The following charts break down the data till we can get a realistic moving rate that you can use for estimation. 

Here is the data for total households with children that moved in 2022. Note the significant differences by region. 

Here is the subset data on those who moved AND left the county:

In our final table, we will make a manual adjustment to identify the moving rate of households that leave the county. Look at the right-hand column and, we suggest, use this number to estimate how many of your families (in your region) might leave the school each year due to moving.  

The largest discrepancy by regions is between the Northeast where only 2.3% of households with school age children are likely to move out of county and the South where nearly 3.4% are likely to move. While the odds of a family leaving the county are proportionately greater in the Northeast than in other regions, this may be simply a result of the counties being typically smaller.  

From the data, we can see that the average across the country of families with school-age children leaving the county is 3%. While some may leave the county and continue with your school, there are likely a similar percentage who move within the county but end up too far away to continue attending. Leaving the county remains a reasonable proxy for leaving the school for projection purposes. Schools can now predict a high of 97.7% in the Northeast to a low of 96.6% in the South is the theoretical maximum that can be expected if the school retains 100% of its children. Even the very best schools are going to need to recruit enough new children to replace the loss of approximately 3% due to moving. 

Of course, we recognize that each school operates within a unique cultural and economic situation, and these external factors vary not only from place to place but from year to year. The very best predictions are likely to come from schools’ tracking their ongoing enrollment statistics and observing the trends over the years. Even if this has never been done before, most schools actually have the data to do the analysis, likely going back several years if not decades. We recommend:

1. Schools use the “moving” data for their region to integrate with their enrollment projections.
2. School meticulously track retention data (total minus graduation minus moving) for the whole school and by grade.