15,000 teenagers in Ireland are working for below the minimum wage.
A study from the ESRI shows that some are earning as little as €7.91 an hour.
Under the law, the minimum wage is currently €11.30 an hour, with those under 18 allowed to be paid 70% of that rate.
But, Dr. Paul Redmond from the ESRI says most employers recognise the value of having young people in the workplace:
"What we find in this research is, if you look at these young workers, the majority - three quarters - are actually on higher wages. So they earn either the full adult rate or they earn in excess of that."
Meanwhile, there are fears that workers on the minimum wage could see their hours cut when the rate increases next year.
It's going up by €1.40 to €12.70 an hour.
Some employer organisations say the rate increase will harm the hospitality and retail sectors where some teenage workers are only earning €7.91 an hour currently.
