Relative age effect, career profiles, and peak market value in elite European football: A retrospective analysis

Relative Age Effect (RAE) systematically favors athletes born early in the competitive year. However, evidence of its persistence and possible reversal in elite football remains limited. This study examined whether RAE persists in Europe's top five football leagues and how birth quartile influences career trajectories and peak market value. Data from 9784 footballers who participated in the first divisions of England, France, Germany, Italy, and Spain between 2012–2013 through 2023–2024 seasons were analyzed. After applying positional filters, the final sample included 4866 players. Birth quartiles were determined according to national cut-off dates. The χ 2 test was used to assess the prevalence of RAE. A cluster analysis (k-means) identified empirical career profiles, and a General Linear Model (GLM) estimated the combined effects of quartile, career type, position, and minutes played on the logarithm of peak market value. RAE persisted significantly, with 30.8% of players born in the first quartile versus 19.4% in the fourth (ratio 1.59). Those born later (Q3–Q4) reached their peak market value at an older age. Four career profiles were identified (i.e., Superstars, Role Players, Squad Players, and Consolidated Elite), with different distributions by quartile. In the GLM, quartile remained a significant predictor of market value. RAE remains prevalent in the European youth development system. After controlling for covariates, later-born players who reach the elite showed a small but statistically significant advantage in adjusted peak market value. These findings suggest that early selection bias warrants structural reform to promote equitable talent development.