The number of schoolchildren with part-time jobs has fallen by a fifth over the past five years.
Figures released by more than 140 local authorities revealed that 29,498 child labor permits were issued in 2012, compared to just 23,071 in 2016.
Employers must apply for these permits to hire staff between the ages of 13 and 15.
Dr Angus Holford, of the Institute for Social and Economic Research at the University of Essex, said pressure to do well in school could be behind the drop in numbers.
He said: “Teenagers are being told more and more that you need to get good GCSEs and A-levels to get a good job long term. Passing the exams you need now is higher on people’s minds.
Geoff Barton, general secretary of the Association of School and College Leaders, said it was “vital” that young people give themselves enough time to study and rest.
But he added: “Properly regulated part-time work is a good way to help young people acquire the skills they will need in their working life.
Norfolk and Dudley in the West Midlands were the main areas for children with part-time jobs, according to BBC Freedom of Information requests.
Figures showed Norfolk County Council issued 1,376 permits in 2016, or 5.2% of children aged 13-15, while Dudley Metropolitan Borough Council issued 471, the equivalent of 4 , 4%.
During the school term, children can only work a maximum of 12 hours per week, including a maximum of two hours on a school day or on Sundays.
Work requiring a permit includes retail work, newspaper tours, waiting at tables, office or office work, and delivering flyers.
The rules are different for babysitting or odd jobs for families and individuals.
But the decline in the number of children working part-time is not only due to academic pressures, it is also due to changing consumption habits.
One of the biggest declines in work permits issued was in Middlesbrough.
In 2011, 101 permits were issued, but in 2016 the number was only seven.
The council said the massive drop was due to a drop in the number of people in the area who had a newspaper delivered to their door.