Children born in the later part of the year have more difficulty in school, finds a new study published in French journal La Revue Économique.
Julien Grenet, an economics researcher at the French National Center for Scientific Research, found that 34 percent of December-born students in France repeat a grade, versus a 17 percent average for the rest of the class.
In elementary school, an eleven-month age gap sets a CP (roughly equivalent to grade one) student back seven spots out of a class of 30, and can lose them another five spots in CE2 (grade three). The struggles continue into high school.
Those with a later birthday are also likely to earn an average of 1.5 percent less during their working lives, putting them at an even more significant disadvantage.
Some European countries are already attempting to rectify the gap. British school-children are divided into classes depending on their month of birth, and the Netherlands allows younger students the option of spending an extra year in kindergarten.