This technical report, coordinated by the National Office of Foresight and Strategy, presents a prospective analysis exploring migration's impact on Spain's demographic, economic, and social evolution from 2026 to 2075. By comparing a central scenario based on current trends with a "low migration" scenario (featuring a 30% reduction in inflows), the study highlights structural risks to the nation's future
.Under the low migration scenario, Spain's total population would shrink by 25%, falling to 40 million inhabitants, with 9 million fewer people in the workforce. Furthermore, economically, potential GDP would decrease by 22% by 2075, a loss equivalent to four times the annual revenue of the Spanish tourism sector. At the same time, essential sectors would face severe labor shortages: approximately 220,000 agricultural farms and 90,000 hospitality establishments could disappear. In this sense, the care sector would see a 28% drop in supply while the demand for elderly care is projected to rise by 60%. Public services are also at risk, with the projected closure of 50,000 classrooms and a deficit of 64,000 medical specialists. Moreover, fiscal sustainability would be compromised, requiring workers to contribute an additional €2,000 annually to maintain current pension levels. Furthermore, rural depopulation would intensify, threatening the survival of over 2,300 municipalities. Conversely, maintaining current migration trends would allow Spain to increase its demographic and political weight within the European Union by 10%.

Ultimately, this technical report provides a comprehensive quantitative framework for informed strategic debate, framing migration not merely as a demographic statistic but as a decisive structural vector that will determine whether Spain remains a dynamic and prosperous nation or faces a slow process of social and economic contraction by the year 2075