"One of the challenges in addressing teacher shortages is the lack of clarity on what a 'shortage' is," says Professor Beng Huat See, co-author of the book Making Schools Better for Disadvantaged Students and Professor of Education Research at the University of Birmingham.

She says there isn't a universal definition, and this affects how a "shortage" is portrayed in policy and the media.

She highlights the following common indicators of teacher shortages.

Teacher vacancies

"The number of advertised teacher vacancies in schools is often taken as a sign of a teacher shortage.

"However, the number of posts advertised does not necessarily indicate an inadequate number of teachers. Several factors can affect teacher vacancies."

Class sizes and pupil-to-teacher ratios

Another way of looking at teacher shortages is by average class sizes and pupil-to-teacher ratios (PTRs).

"Many countries typically use PTRs as indicators of a shortage even though there is no standard measure of what is considered a large class or high PTR.

"PTR is a measure of the level of teaching resources available. It does not take into account teachers' working hours or hours spent teaching.

"Countries such as Singapore, China, and South Korea can keep PTRs low despite larger than average class sizes. This is probably because they teach fewer classes, which means fewer hours of teaching. These countries tend not to be affected significantly by a shortage of qualified teachers.

"Generally, countries where education is reported to be significantly affected by a teacher shortage – such as Brazil, Colombia, and Vietnam – have high PTRs and larger class sizes.

"Countries with low PTRs and smaller class sizes – such as Finland, Slovenia, Estonia, and Cyprus – do not report major issues with teacher shortages.

"However, there are cities like Shanghai and Buenos Aires with large class sizes but low PTRs that do not report serious teacher shortages."

Qualified teachers

A further common indicator of teacher shortages is a lack of qualified teachers, says Professor See. This is troublesome because of the way different countries define who is or isn't qualified:

"In some countries, teachers with a teaching certificate are considered 'qualified,' while in other countries, teachers teaching a subject for which they are not trained – or which is not their degree subject – will be considered 'unqualified.'"

Despite no universal definition of what makes a teacher shortage, the supply of teachers doesn't match the demand in many countries and regions – from South Africa and China to the U.S. and New Zealand.

This isn't a new issue.

"There have always been periods of teacher shortage and surplus," says Dr. Reece Mills, Associate Professor of Education at Queensland University of Technology.

"In Australia, there are records of this dating back to, for example, a slump post-World War II in 1945."

Citing a chapter by Professor John Howson in Exploring Teacher Recruitment and Retention, a book she co-edited, Professor Tanya Ovenden-Hope, Dean of Place and Social Purpose and Professor of Education at Plymouth Marjon University and Marjon University Cornwall, highlights that shortages were apparent in England post-war:

"This was rectified with a massive pay increase to bring teachers in line with other professions," she says.

Complexity

In modern times, the cause of teacher shortages is more complex than low wages.

Professor See says that teacher demand and supply can be influenced by many factors. These include:

• Birth rates
• The economic context
• The supply of graduates
• Policy incentives for recruitment and retention
• Changes in education policies

For example, "government policies can increase or decrease teacher demand and supply almost overnight by changing mandatory class sizes, pupil-to-teacher ratios, entry requirements for teacher training, adjusting the number of training places available, reforming the way schools are funded, and changing the number and types of schools," she says.

Economic context

The strength of the economy is having a big influence on teacher recruitment and retention in the U.S., according to Dr. Todd Whitaker, Professor of Educational Leadership at the University of Missouri and author of 65 books, including How to Get All Teachers to Become Like the Best Teachers.

"Because the economy's so good, other industries have a lot of money available to attract teachers and those with an educational background," he says.

"If it's hard to get a job, then only the very best teachers can leave the profession. Instead, when anyone can get a job, everyone can leave."

Dr. Whitaker highlights further factors that are affecting teacher recruitment and retention in the U.S.:

"Politically, there's a demonization of teachers. People make up ridiculous stories about them.

"Teaching is also really hard. Its intensity and significance make it much harder than most jobs."

Workload

"Teachers are reportedly leaving the profession due to more acute concerns with workload and student behavior," adds Dr. Mills.

"Teachers' time is taken away from them by administrative tasks such as data entry. Some teachers face occupational violence and are not well supported to manage this by their employer."

Dr. Mills also highlights the changing nature of careers in the 21st century and an aging workforce as factors:

"Fewer people are becoming life-long teachers and instead are using teaching as a stopgap in response to the boom and bust of other industries.

"In Queensland, Australia – where I live – the teacher shortage 'alarm bells' were ringing in 2015, when more than half the teaching population were aged 45 years or older."

Deprofessionalization

The perception of teaching can affect teacher recruitment. In written evidence to the U.K. parliament in 2020, Professor Ovenden-Hope highlights that a "deprofessionalization" of teaching means it may no longer be a popular career choice for graduates.

"We do not use the term 'training' in Australia," adds Dr. Mills.

"It reduces the teaching profession to a technical endeavor, rather than a professional one. This is part of the problem, as teachers have lost a lot of respect and professionalism in my country."

Staff turnover

Many of these factors – such as the lure of alternative, more highly paid careers, bigger class sizes, challenging workloads, and public perceptions of teaching – are causing teachers stress, lowering job satisfaction, and increasing staff turnover.

For example, in England, 1 in 10 teachers leave the profession within one year of qualification, while 4 in 10 leave within 10 years.

However, high turnover isn't a cause of teacher shortages in all parts of the world.

In sub-Saharan Africa, fewer than 1 in every 20 teachers leave the profession each year. These figures include those who leave due to ill health, misconduct, and retirement.

Researchers suggest lack of funding causes teacher shortages in these countries, as it takes a long time to replace departing teachers.

Larger class sizes, schools hiring underqualified teachers, and decreases in the quality of learning experiences are major short-term impacts of a teacher shortage, says Professor Etta Hollins, Professor Emerita in the Division of Teacher Education and Curriculum Studies at the University of Missouri-Kansas City, and author of several books including Learning to Teach in Urban Schools.

These impacts then increase teachers' and school leaders' workloads, as Professor Hollins explains:

"Protecting students from the risk of learning loss during a teacher shortage requires rethinking the organization and delivery of the curriculum, pedagogical practices, student learning experiences, and the social arrangements in the classroom.

"This is extensive work that requires changes in teacher preparation and teacher professional development, and collaboration among teacher educators, classroom teachers, and school administrators."

Poor outcomes for pupils

In the longer term, continued teacher shortages in the U.K. have led to poor outcomes for pupils, says Professor Ovenden-Hope:

"The increase of temporary contracted unqualified staff to infill the gaps in classrooms left by the teacher shortages has impacted on pupil progress."

This negatively affects teachers' morale. Along with increased workloads, this can result in more teachers leaving the profession. This makes teacher shortages worse.

"In Queensland, unqualified pre-service teachers are now permitted to teach in classrooms while studying," adds Dr. Mills.

"This raises questions about how much supervision and support they receive, and from whom, early in their career. It is probable they will experience work stress and burnout, further exacerbating the teacher shortage."

Hardest hit schools

Dr. Mills also highlights that pupils and teachers in "hard-to-staff" schools are generally hit the hardest by the impacts of teacher shortages.

"In Australia, this generally means those further from the metropolis – i.e. schools located in regional, rural, and remote locations. Or urban schools with diverse student populations.

"We also have certain subjects that are harder to staff than others, with science, mathematics, and languages generally on the top of the hardest-to-staff list."

It's a similar situation in the U.K.:

"The shortages appear greater in rural, coastal, and ex-industrial locations," says Professor Ovenden-Hope, whose research focuses on the challenges for coastal, rural, and small schools.

Opportunities

The impacts of teacher shortages might not all be negative where class sizes increase, explains Professor Hollins:

"This situation provides opportunities for developing students’ collaboration, cooperation, leadership, responsibility, respect, and personal integrity.

"For example, students can complete learning tasks as individual homework, and receive feedback or an evaluation by three or more peers during the class meeting based on an assessment tool developed by teachers.

"This social arrangement allows the teacher to instruct and monitor learning for a larger number of students while minimizing the risk for learning loss."

Although we've seen how the causes of teacher shortages vary by country and region, Dr. See highlights several common ways governments and policymakers could make teaching as a career more attractive.

Increasing pay

One way is increasing the level of pay so it's on a par with other graduate occupations.

"This is better given as salary increases rather than 'quick fixes' such as temporary incentives or bonuses," she says.

Reducing teaching hours

Another is improving teachers' well-being by reducing teaching hours, without reducing overall working hours:

"Teaching is a very intensive job, and relentless pressure from the principal, parents, and pupils can take a toll in the long run."

Increasing learning resources

Dr. See also suggests increasing teaching and classroom resources, which she says is likely to be less expensive than increasing pay or offering financial incentives.

Addressing student behavior

Policies that can help address abuse and intimidation by students can help too:

"Countries that have a policy of using special schools, rather than inclusion of most children with disabilities or learning challenges in mainstream settings, tend to have less shortages, perhaps because of fewer classroom challenges in mainstream schools," she says.

Professionalization

Professor Ovenden-Hope says there needs to be a rethink of the way the government perceives teaching in the U.K.:

"Reregulation is needed, with professional-level pay and conditions, including autonomy for the profession, utilizing professional bodies – such as the Chartered College of Teaching in England.

"Teaching should be treated as a profession and take responsibility for itself, as other professions do – for example, law, medicine, etc."

Employment benefits

Meanwhile, some schools in the U.S. are moving to four-day weeks. This is often primarily for financial reasons, but it can also help with teacher retention, says Dr. Whitaker.

"Incredibly, this has helped student and teacher attendance. Districts that have gone to a four-day week take teachers from districts with five-day week schools all the time."

Employee benefits more common in the private sector, such as on-site childcare, could also help retain teachers, says Dr Whitaker:

"It's just we haven't thought about serving teachers in the same ways that many companies have done.

"Legislators could do this tomorrow if it was a priority."

Alignment with other policies

A joined-up policy environment is another element governments and policymakers should focus on when dealing with teacher shortages, says Dr. Rees:

"For example, in Australia, teachers might be incentivized to move to a regional school, however, there is no housing available for them to live there."

Although many of the possible factors that cause teacher shortages are outside the control of individual schools, there are some things that school leaders and even parents can do to reduce staff turnover at a local level.

"Some of our research has shown that school leaders – i.e., principals – play a major role in cultivating a school culture that encourages teachers to stay," says Dr. Mills.

"This generally involves putting the teachers first – listening to their voices and backing and supporting them however possible."

Dr. Whitaker, a former teacher and school principal, agrees:

"Before the pandemic, the two biggest reasons teachers left were because of an ineffective leader, or because they couldn't manage their class. The world changed, and guess what? These are still the two biggest reasons teachers leave."

He highlights how important it is for principals to help their teachers become more effective:

"One person at a time, one school at a time, one classroom at a time. That's where the real change takes place.

"It isn't saying 'manage your class' or 'raise your test scores.' It's teaching you how to do it."

Making teachers feel valued

Dr. Whitaker adds that school leaders and parents need to work hard to make sure teachers feel valued:

"We need to treat teachers special because they are special.

"Let's say I have 25 students in class and the families of those students are supportive and understanding and we work together well.

"That helps me want to stay as a teacher."

Journal articles:

• Dissatisfied but nowhere to go: teacher attrition in the context of mass unemployment in Sub-Saharan Africa by Paul Bennell in Globalisation, Societies and Education
• How are teacher shortages in hardest-to-staff schools represented in (inter)national policy documents from England and Australia? by Reece Mills et al. in Asia-Pacific Journal of Teacher Education
• Impacts of the four-day school week on high school achievement and educational engagement by Paul N. Thompson et al. in Education Economics
• Teacher shortage: an analysis of the rural teachers living subsidy policy on teacher attraction and retention in rural Western China by Jinqiu Jiang and Sun Yee Yip in Asia-Pacific Journal of Teacher Education
• 'What's wrong with me?': an autoethnographic exploration of teacher stressors and burnout by S. Luke Anderson in Teachers and Teaching

Browse all education and teaching journals and articles

Books and book chapters:

• Addressing the Teacher Shortage: Recruiting our Next Generation of Teachers by Kimberly Eckert in Flip the System US edited By Michael Soskil
• Exploring Teacher Recruitment and Retention: Contextual Challenges from International Perspectives edited By Tanya Ovenden-Hope and Rowena Passy
• Making Schools Better for Disadvantaged Students: The International Implications of Evidence on Effective School Funding by Stephen Gorard, Beng Huat See, and Nadia Siddiqui
• Rethinking Field Experiences in Preservice Teacher Preparation: Meeting New Challenges for Accountability by Etta R. Hollins
• What Great Teachers Do Differently: Nineteen Things That Matter Most by Todd Whitaker

Browse books for teachers, educators, and leaders

Blogs, articles, and insights

• 12 shifts to move from teacher-led to student-centered environments (Routledge)
• Why does teachers' assessment literacy matter? (Routledge)
• Opinion: MPs are right - teacher recruitment and retention are in crisis (Plymouth Marjon University)
• Avoiding burnout through a mindset of acceptance (Routledge)
• Confronting child hunger
• Getting more girls in STEM