Spain’s government has picked a side in the West’s biggest political battle — and it insists it has the data to back it up.While most Western governments race to tighten borders, Prime Minister Pedro Sánchez is doubling down on open migration, armed with a technical report making the economic case for why pulling back would be a serious mistake.According to their findings, a 30% annual reduction in migration flows would shrink Spain’s GDP by 5% within a decade, 14% by 2055 and 22% by 2075, according to projections drawn up by the National Office of Foresight and Strategy (ONPE).That is not a forecast any government would want on its hands.The report lands the same week Spain hit a record 22 million employed workers — a milestone experts partly attribute to sustained migration flows that have accelerated sharply since the pandemic.Farms, villages, classroomsThe consequences of a migration clampdown would reach far beyond the headline GDP figures.More than 220,000 agri-food farms could be abandoned within 50 years or nearly three in ten of those operating today, deepening Spain’s chronic rural depopulation crisis.Up to 2,300 small municipalities, around 20% of the total, could disappear entirely.Provinces such as Orense and Zamora, where the average age already exceeds 50, face demographic conditions the report compares to the Siberian steppe.The knock-on effects compound rapidly. Fewer workers means fewer children in schools — the analysis projects the closure of 32,000 primary classrooms and 18,000 secondary ones.Rural primary care centres would follow, stripping remaining residents of basic services and accelerating the very decline they are trying to reverse.Who is filling the gaps?Migrant workers are already propping up sectors the domestic workforce will not go as eagerly.In agriculture — where poor conditions on farms in Huelva, Almería and inland Catalonia have long drawn criticism from rights groups — they fill roles that would otherwise go empty.The report argues that migrants generate between 15% and 25% of the annual increase in average income and do not, contrary to popular assumption, depress the wages or employment prospects of native-born workers.The politics are equally charged. An express regularisation scheme introduced in 2018 — due to be revoked in June — has granted near-automatic residency to around 240,000 Venezuelan citizens.Sánchez’s deal with Podemos at the time also unlocked an extraordinary regularisation programme, pushed by groups such as Regularisation Now, which has long campaigned against exploitative conditions on Spanish farms.No doctors, no carers in an ageing countryThe healthcare system would feel the strain acutely.With fewer migrant workers arriving, the supply of care could fall by 28% — just as the number of elderly dependents rises by nearly 60%, according to ONPE analysts.In cities such as Madrid, 90% of carers are already of migrant origin.Meeting future care demand would require around 483,600 additional workers on top of current employment levels, analysts say, citing research by BBVA, the University of Cambridge and the OECD.Those studies are now over a decade old — meaning the gap may already be wider than the figures suggest.The medical workforce faces its own crunch.The Technical Working Group on Migration, made up of nine academics from Spanish universities, estimates a clampdown would reduce the country’s doctor count by 64,000 specialists — a serious blow to a public health system already battling growing waiting lists and a profession currently on general strike over working conditions.Pensions: Spain’s eternal economic tabooThe pension system adds another layer of pressure.By 2075, analysts estimate each beneficiary would need to contribute an additional €2,000 to maintain current benefit levels — though they note a paradox: public finances would actually peak between 2050 and 2060, as Generation X, born during Spain’s late Franco-era baby boom, completes its retirement.After that, the fiscal cushion deflates rapidly.