The education sector in England is facing a teacher supply crunch. The number of pupils at state-funded secondary schools in England is expected to grow by nearly 160,000 over the next three years. In order to maintain current teacher-to-pupil ratios, this would imply a need to recruit nearly 11,000 additional teachers before 2024, on top of replacing the 15,000-20,000 secondary school teachers that leave the profession each year.

This is a major source of pressure within the education system at a time when it is still stretched by having to manage Covid cases within classrooms, while trying to make up for the effects of lockdowns on pupils’ education.

We are unlikely to be able to recruit our way out of this crisis. On average over the last decade, recruitment shortfalls have meant 1,000 secondary school teachers are added to the shortage each year.

But reversing the decline in teacher retention would go a long way towards solving the shortfalls and easing the pressures schools and the government face. If retention rates had remained stable at 2010 levels, with only around 6% of teachers leaving per year, there would have been on average 2,800 fewer secondary school teachers lost to the profession per year over the last five years. A retention boost of this scale would have more than closed the recruitment shortfalls experienced over recent years. The scale of the loss has declined since 2015, but evidence of growing concerns about teacher wellbeing currently suggest that these improvements may be short-lived.

Improvements in continuing professional development (CPD) have been highlighted as one of the critical factors for keeping teachers in the profession. Analysis from the Education Policy Institute concluded that, while there is significant uncertainty, it was plausible that a 35-hour entitlement could lead to up to 12,000 additional teachers remaining in the profession each year.

Our analysis suggests that increasing the provision of high quality CPD for teachers is likely to quickly prove cost effective for the education system, with benefits from improved retention likely to outweigh costs within two to three years.

It costs the government around £24,900 to train a new teacher. Given the cost of an additional day of high quality CPD is around £150-£450, it would save government money if the additional day of CPD improved retention rates by just 0.6-1.8% pts. The incremental cost of providing 35 hours of high quality CPD (estimated by the Education Policy Institute) would be offset provided that retention rates are improved by just 2.0% pts.

Existing evidence suggests that improvements in retention from increased CPD are likely to be at least 2% pts and possibly more. This suggests that it is plausible that savings to the government from improved staff retention will outweigh the costs from increased teacher CPD.

The recently launched Early Careers Framework (ECF) – providing early career teachers with a two-year package of structured training and support – and the announcement of funding for 150,000 high-quality National Professional Qualifications (NPQs) for teachers in all state schools provide promising signs that the government is working hard to improve the provision of CPD for teachers.

However, more investment could pay dividends for the government both now and in the future. Building on recent progress to meet Wellcome’s call for 35 hours of high-quality CPD for every teacher every year, is not only likely to help address the impending teacher supply crunch, but is likely to save the government money, improve the quality of teaching provided in our schools and improve outcomes for children in the longer term.

Read the report in full