There could be an oversupply of school teachers in New Zealand next year, especially if border restrictions remain strict, the Ministry of Education says. 

Unusually high numbers of teachers have stayed in the profession during the pandemic, partly because they have been unable to head off on an OE (overseas experience). 

On average about 11 per cent of teachers leave the profession each year in New Zealand, dropping to 10 per cent in 2020. 

This year the Ministry forecast just 7 per cent of secondary teachers and 8 per cent of primary teachers would leave by the end of 2021. 

Those rates did not take into account the vaccine mandate - but even if another 2 per cent of teachers left, an excess of teachers was still possible, the Ministry found. 

The latest teacher demand and supply planning projections, released this afternoon, said teaching supply had been "fundamentally disrupted" by the pandemic leading to a spike in teachers staying in the classroom. 

The Ministry warned its projections had been created under "unprecedented levels of uncertainty", most notably around border settings here and internationally as well the economy and the vaccine mandate. 

It offered two possible scenarios, depending on factors like the economy and border restrictions. 

If border restrictions eased next year and more teachers left the profession, the Ministry forecast there could still be up to 620 extra primary teachers, but a shortage of 210 secondary teachers. 

But if border restrictions stayed strict, and fewer teachers left, there could be up to 1710 extra primary teachers and 1000 extra secondary teachers. 

The projection tool was developed in 2018. Since then, there had been big increases in both supply and demand for teachers, the report said. 

In 2018 and 2019 the growth in supply was largely due to more new teachers and former teachers returning to the classroom, many coming from overseas. But this year, higher retention was behind the increase. 

The Herald has also previously reported on many Kiwi teachers returning from Covid-torn countries, adding to lower vacancies this year. 

With more enrolments in teacher training, 2022-2024 is also likely to see a climb in new graduate teachers, the Ministry's report said. 

The report did not drill down into subject specialities - but said ongoing shortages were likely in science, technology, engineering and maths as well as te reo Māori and Māori-medium teaching. 

Demand for secondary teachers was likely to grow until 2025, while demand for primary teachers was expected to fall after 2023. 

Vaccine mandate impact still not certain 

The Ministry's modelling didn't account for the impact of the vaccine mandate, which requires all on-site teachers to be fully vaccinated by January 1. But its initial analysis showed in most scenarios there would still be enough teachers on a national scale, even if 2 per cent of teachers refused to get the jab. 

The latest data suggests about 2.4 per cent of teachers have not yet been vaccinated. 

If 2 per cent of the workforce dropped out, the Ministry said, the primary school sector would be short by just 110 teachers even if borders opened up and more teachers left the profession. In that scenario secondary schools could be short by 760 teachers. 

But if borders remained closed next year, there would still be up to 980 more teachers than needed for primary schools nationally, and 450 more secondary teachers. 

The Ministry acknowledged supply could be unevenly distributed, leaving shortages in some areas. 

That's likely to be exacerbated by the vaccine mandate - such as in Northland, the least-vaccinated area, where 6.7 per cent of teachers are unjabbed, compared to 2.4 per cent nationwide. 

The Ministry's report said while the outlook was positive nationally, it would keep providing "targeted support" where needed. 

It also outlined work done to grow teaching supply, including expanding the voluntary bonding scheme to decile 2 and 3 schools in Auckland, STEM subjects and te reo Māori. 

The Ministry had also secured a border exception for 300 teachers from overseas - although it's not clear how many teachers have arrived via this pathway.