Spain needs four times more migrants to sustain pensions, AIReF warns

Spain would need to quadruple migrant inflows to sustain its pension system

The AIReF (Spanish Independent Authority for Fiscal Responsibility) stated in its report on public administration sustainability that one million additional migrants per year would be required to prevent the dependency ratio from worsening. In 2024, 350,706 foreigners entered Spain according to INE's Continuous Population Statistics. The calculation is simple and the result uncomfortable: current flows would need to be multiplied by 3.85. The independent body admits that even its base scenario, which is much more modest, fails to avoid population aging.

The Spanish pay-as-you-go system relies on a demographic pyramid that ceased to be a pyramid decades ago. With near-zero natural growth and the baby boom generation retiring en masse, migration is the only net source of active population. AIReF projects the total population will rise from 48.6 million to 52.1 million by 2050, but the working-age group (16-66) will peak at 33.6 million in 2029 before falling to 30.6 million in 2050. The dependency ratio would escalate to 70.5% by 2053.

What exactly does the AIReF report say about pensions?

The document, titled Opinion on the long-term sustainability of Public Administrations, analyzes three scenarios for net migratory flow. Until 2029, an average of 319,700 people per year; until 2039, 273,600; until 2050, 279,000. The average between 2023 and 2050 remains around 288,000 annually. These figures are well above those used by the former Minister of Social Security in 2023 to justify reforms: between 200,000 and 250,000 until 2035, rising to about 450,000 by 2050. Official forecasts and those of the fiscal authority never aligned.

Fedea researcher Miguel Ángel García summarizes it without embellishment: the figure of one million is necessary to prevent a reduction in the active population, and achieving it is "very complicated." First, because such a flow does not seem available. Second, because even if it existed, the risk of integration problems is high. AIReF does not delve into this aspect, but its numbers highlight it.

The problem is not just how many arrive, but what they do

Jesús Fernández-Bravo, president of Economistas Asesores Laborales, introduces the variable often omitted from headlines: job quality. "It is essential that immigrants have access to stable, high-quality jobs to maximize their contribution to the system," he notes. The unemployment rate for foreigners in Spain is 17.43%, with a clear gap between those from the EU (13.94%) and non-EU countries (18.78%). Of the 2,921,205 foreign workers registered in March, 217,516 were listed as job seekers. A contingent that contributes, yes, but with intermittency that can erode the system's base.

The underlying debate is whether the pay-as-you-go system can be sustained with a non-growing active population. The technical answer is no, unless there is acceptance of increasing tax pressure, a reduction in the average pension, or a combination of both. The political answer is that no one wants to say these things out loud.

Why doubts arise over migrants paying for pensions

An argument common in discussions on this topic is: if migrants come from countries where their own pension systems fail, why should they sustain the Spanish one? This objection contains a logical trap—contributing is not a personal choice but a legal obligation when employed—but points to a real problem: precariousness and the informal economy reduce the effective contribution base. A worker with a temporary contract and low salary contributes less than what the system needs to pay an average pension.

The other flank of the debate is social spending. It is argued that part of the migrant population consumes health, education, and social services resources before generating fiscal returns. Available evidence is mixed and depends on the time horizon measured. In the short term, integration costs are real. In the long term, net contribution depends on employment rates and the age structure of newcomers.

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AIReF does not design migration policy; it merely puts numbers on the table. And the numbers indicate that the base scenario—which assumes current flows—does not prevent the dependency ratio from continuing to rise. One million annual migrants is the figure needed to freeze the problem, not solve it. With birth rates where they are and the baby boom retirement underway, any government facing this must choose between raising taxes, lowering pensions, or accepting significantly higher migration flows. Probably all three at once.