Poorer pupils in England and Wales are “significantly” behind their peers, the report says.
Research by the Education Policy Institute (EPI) found that in 2019, before the pandemic, the gap between poorer pupils and their peers was 22-23 months in Wales and around 18 months in England.
The gap has narrowed slightly in both countries since 2011, but the EPI said progress appears to have “recently stalled”.
The biggest in Wales lack of spaces by area reached 25-28 months, EPI showed. In England, the largest attainment gap of around 25 months was found in Blackpool.
Students living in long-term and persistent poverty lag even further behind their peers in both countries. In England, the persistent disadvantage gap was equal to about 23 months of schooling, while in Wales it was 29 months.
There has been almost no improvement in this measure over the past decade. The EPI said policymakers need to do more to reduce the gap, particularly in Wales, where it is “significantly worse”.
The researchers said comparisons between England and Wales could be “difficult” because the English qualification was reformed in 2015, while performance measures in the two countries have changed over time.
But the EPI said that while Wales had a wider attainment gap at GCSE level than England, progress in closing the gap in both countries had been “modest” over the past 10 years. He called for a renewed focus on narrowing the gap in schools.
The study found that pupils from poorer families were significantly less likely to achieve the top quintile of GCSE scores and more likely to be in the bottom quintile in both countries.
The EPI said local authorities in Wales needed to take action on poorer areas of England that had managed to close the gap in disadvantage over time. It says that targeting extra funding to poor schools has proven effective in reducing the disadvantage gap, and that more funding should be targeted specifically at students living in persistent poverty in both countries.
EPI said measures such as attracting high-quality teachers to poor areas through salary bonuses and individualized and small-group instruction have also been shown to reduce achievement gaps.
The government’s flagship national tutoring program aims to help pupils catch up during the pandemic, but the decision to drop attention to the poorest pupils has been criticized by social mobility experts.
The government has also announced a teacher promotion award where eligible maths, physics, chemistry and computer science teachers can receive a £3,000 award to teach in deprived areas from 2022 to 2025.
Luke Sibietta, research fellow at EPI, said: “The gap in educational outcomes between poor children and the rest is too wide in both England and Wales.
“But the results for Wales are particularly worrying, with poor children on average almost two years behind taking GCSEs, compared to 18 months in England. And long-term deprived children in Wales are nearly two-and-a-half years behind, compared with just under two years in England.
“Politicians in both countries should redouble their efforts to give poorer children the best chance in life, and Welsh politicians should consider whether lessons can be learned from the best-performing areas of England, where the gap is much smaller.”