It is easy to see the costs of staff turnover solely in financial terms.

The cost of things like placing an advertisement or attending a recruitment fair certainly add up; but in practice, there are many other costs that have a significant impact on the effectiveness and reputation of a school.

The first thing to note here is that a certain amount of staff turnover is actually healthy for a school. It is an opportunity not only to introduce new ideas and experience, but also it can provide avenues for internal promotion and progression.

If turnover is too low (say, less than 5 per cent a year), it is possible for a school to stagnate.

However, if it is too high (over 25 per cent of staff), it can be detrimental to the effectiveness of a school. It is generally recognised that the sweet spot, for international schools at least, is about 10 to 15 per cent per year.

So what are the problems with turnover when it strays beyond that sweet spot? While the financial cost is not the only issue, it can’t be ignored.

The fees involved can be significant, particularly for international schools. At Kellett, where our turnover ranges from 7 per cent to 12 per cent per year, the accounts show that the total cost of recruiting 13 new staff for the start of this academic year was HK$1,543,000 (approximately £150,000) - about £11,500 per appointment.

These costs include advertisements, overseas recruitment trips, interview expenses and the costs of onboarding, such as the cost of placing staff in temporary accommodation on arrival.

Whilst this figure is likely to reduce going forward as we go on fewer recruitment trips and move from face-to-face interviewing to conducting more interviews by video-conference, it remains a significant cost.

Teacher recruitment: The cost and impact of high staff turnover

In addition to the financial hit, these five factors also take their toll: 

1. The time it takes to replace staff

The fact is that recruitment takes time. In my experience, depending on the size of the school and the level of turnover, it can take up a significant proportion of school leaders’ schedule for about three to four months a year.

Last week the team at Kellett School completed the recruitment for a middle leadership pastoral role in our senior school. This entailed three senior staff each spending about three hours evaluating applications and meeting to decide the shortlist; and five hours interviewing the candidates (a combination of in-person and by Zoom): a total of 24 hours of SLT time.

This was in addition to the six hours put in by the HR team placing adverts, updating the job section on the school website, setting up the application portal, sifting out unqualified candidates and responding to queries.

Looking ahead, there will be a further four to six hours of admin for the HR team as they process the successful candidate’s paperwork (reference and qualification checks, safeguarding clearance, visa applications, teacher registration documentation, etc) before they and teaching colleagues begin the onboarding and induction process - typically, a further 10 hours.

2. Your reputation with parents

Parents, understandably, want continuity of teaching for their children. Parents want consistent standards from year to year, and staff retention goes a long way to ensure that this is the case.

In senior schools, it is helpful for a teacher to see a student through the two years of their GCSE, A-level or International Baccalaureate Diploma Programme course. It takes time for teachers to get to know the individual foibles of their students and vice versa. Continuity of teachers not only avoids going back to “square one” and building a new relationship, but it also allows the bond between teacher and student to grow even stronger.

The impact of turnover on the reputation of a school is even greater if there are frequent changes in the school leadership team. The average tenure of a school principal in Dubai while I was there was less than three years, which means that in a significant number of schools there, parents and staff have to adapt to a new direction or leadership style on a regular basis.

3. Your reputation with teachers

Teachers looking to move to work abroad would be well-advised to research the level of turnover in the schools that they are considering. Staff turnover rates can be indicative of how good the school is as an employer in terms of salary progression, benefits and working conditions.

During my time as chair in the British Schools in Dubai group, I was aware of schools that had an annual turnover of about 40 per cent of staff, which meant that nearly all of their faculty did not renew their contract after their initial two-year period.

Some of these schools, unfortunately, rely on attracting a stream of unwary new recruits from overseas, over-promising and under-delivering. In these cases, the high turnover rates serve as a major red flag for job-seekers. Conversely, most schools that look after their staff will have relatively low levels of staff turnover.

4. The time it takes to build a team

It takes time to build an effective team. If there are too many changes of personnel, a department or year group team never gets to gel and can be trapped in a perpetual cycle of what psychologist Bruce Tuckman describes as ”reforming” and “storming”.

Conversely, if there is sufficient staff retention, a team might be able to onboard a new colleague every year or so without it having an impact on the effectiveness of the team.

Indeed, teams can benefit from being challenged by the new ideas at the “storming” stage and move swiftly on to the “performing” stage, where they can have the most impact on learning outcomes for students.

5. The lost sense of ‘soul’

Staff turnover is one of the most important factors in determining the soul of a school. Schools are ultimately about relationships: between students and their teachers; between colleagues; and between parents and the staff.

Schools that have souls are ones where students build a bond with the teachers who guide them through their formative years. They help teachers to feel part of something greater than themselves where collectively staff are able to make a difference - and that takes time and commitment.

For a school to develop a soul, change needs to be incremental: there has to be sufficient that is familiar for everyone to feel that they belong, but enough signs of progress that indicate that the organisation is not stuck in a time capsule. This is a particular challenge for international schools where the nature of the demographic is often transitory. In this context, it becomes all the more important for schools to provide stability for their communities, and to do this they must retain their staff.

Mark S Steed is the principal and CEO of Kellett School, the British International School in Hong Kong; and previously ran schools in Devon, Hertfordshire and Dubai. He tweets @independenthead