Researchers looked at students who were in the third through eighth grades during the COVID-19 lockdown.
The data showing kids fell behind significantly in reading and math. Thomas Kane is a Harvard University Professor of education and economics.
He said "Nationally, students lost about half a year learning and math in about a quarter of a year, learning and reading. But the important thing is there were some communities, especially high poverty communities, that lost a lot more like a year or a year and a half worth of learning."
He says New York City public school students fared worse than students in many other parts of the country.
Professor Kane says catching up in just one school year would be impossible.
He says after-school tutoring and summer school are essential.
New York City did launch a Summer school program called summer rising in 2021.
Kane said, "It's essential that students receive additional instruction either during the school day with tutors or longer school year or summer learning."
There's more, he says the study also reveals parents are not aware of this problem.
Kane said, "Only a quarter of parents believed that their child had suffered any achievement loss as of fall 2022."
And only 9% of parents were concerned about whether their children would catch up.
So it's important for parents to realize that they're probably over-optimistic about what it's going to take in order to recover from these losses.
The researchers have a sense of urgency fearing this learning loss will become permanent if schools and parents do not expand learning time this summer and next year.