It should be relatively straightforward to identify periods when a larger number of secondary teachers are going to be needed to teach growing numbers of secondary pupils. After all, we can see the increase in primary pupil numbers several years in advance - eventually, they move into secondary schools. Yet, amidst all of the reforms to education over this decade, it is only relatively recently that this fundamental issue has started to receive the attention it deserves.

The growing demand for teachers - created by rising pupil numbers as well as policies that have increased the demand for certain subject specialists - comes at a time when teachers’ working hours appear to have been increasing and their real-terms pay has been falling. This isn’t a great advert for attracting new recruits into the profession, in spite of how important and rewarding teaching can be. The government has struggled to hit its recruitment targets for secondary teachers for the past five years.

So, how can we ensure that there are enough skilled, motivated and committed teachers in our schools, across different phases, subjects and diverse geographical areas?

The National Foundation for Educational Research (NFER) has been exploring these issues for several years, arguing that greater attention needs to be given to teacher retention, not just recruitment. The proportion of working-age teachers leaving the profession has been increasing, and every teacher lost to the profession means one more needs to be recruited and trained.

This morning, we published a major new research report, Teacher Workforce Dynamics in England, undertaken with grant funding from the Nuffield Foundation. It provides a detailed analysis of the factors associated with teacher retention and turnover, what happens when people leave the profession, whether they return, and how teaching compares to nursing and policing. The report makes a series of recommendations - for school leaders as well as the government - about how to improve retention.

It is clear that nurturing, supporting and valuing teachers is crucial to making teaching an attractive and rewarding career choice. Along with the quality of the school leadership and a teacher’s sense of autonomy, this kind of environment helps to improve job satisfaction - a key motivator for teachers to remain in the profession.

Cutting teacher workload

So, how important is the workload challenge? Our research highlights the extent to which teachers are working significantly longer hours during term time than other public sector professions (nursing and policing), which, in itself, should raise concerns about their health and wellbeing. Many teachers are unhappy with the amount of leisure time they have and there is demand for more part-time working, even if it means taking a cut in pay.

But the issue of workload is complex - working hours alone are not a strong predictor of whether teachers will leave the profession. It’s when those hours become “unmanageable” that teachers opt to leave. A significant proportion of secondary teachers reduce their working hours when they leave and job satisfaction soars, despite a drop in pay.

There are many potential solutions and some are already being explored. Reducing workload, creating opportunities for more flexible working, targeting financial incentives on those most likely to leave, providing more support for inexperienced teachers and monitoring (and addressing) staff satisfaction and wellbeing are all likely to make a difference. There is a role for both senior leaders as well as the government in tackling these challenges.

Attracting and retaining high-quality teachers - particularly in secondary schools - is a challenge that is likely to continue to grow over the coming years, but it is fundamental to delivering a high-quality education for children. It is, arguably, the most important challenge facing our education system today.

When they leave, well over half of our working-age teachers remain working in the education system - they are committed to improving outcomes for children and young people. Let’s encourage more of them to stay, and offer those who have left the prospect of an exciting, rewarding and manageable career that they want to return to. In doing so, we will undoubtedly make it a profession that new recruits also want to be a part of.

Carole Willis is chief executive of the National Foundation for Educational Research (NFER). The Teacher Workforce Dynamics in England research report is available to download from NFER’s website here.