Enjeux budgétaires et démographiques dans l’Enseignement

Population ageing is one of the most significant demographic transformations of our time, with far-reaching consequences for public finances. In this paper we study the impact of ageing on the budget of education in the French-speaking community of Belgium. As the proportion of older teachers increases, the government faces mounting wage cost due to the seniority premium (the wage drift). Simultaneously, natality decline shrinks the school-age population, which reduces the budget dedicated to education (the revenue drift). These dual pressures—rising expenditures and potentially declining revenues—pose a strategic challenge for budget deficit. Without proactive reform, the French speaking community risk facing unsustainable debt trajectories. Our main contribution is to use administrative data over the period 2012-2024, to estimate the Noria effect which is the impact on the total wage bill of the continuous turnover of high-paid outgoing and low-paid incoming teachers. We also study the job replacement rate to measure the impact of the turnover on the pupil-teacher ratio. Understanding the Noria effect and the job replacement effect in the past helps in budgeting for future payroll in the context of rapidly ageing workforce. We further discuss how best to address the budget crisis without sacrificing teaching quality.