The dissertation assesses the contribution of three distinct institutional features of the schooling system to the inequalities of access of higher education: the selectivity of access of higher education, teacher feedback to Grade 12, and admission rules to selective post secondary programs. I adopt a broad conception of inequalities, including those that stem from high school tracking as well as from socioeconomic background. The analysis is based on unique French administrative data and findings are in reference to the French context.Cette thèse évalue la contribution de trois caractéristiques institutionnelles du système scolaire aux inégalités d'accès et d'orientation dans le supérieur : la sélectivité de l’admissibilité au supérieur, ...