Short answer: In most advanced economies today, an abrupt stop to immigration would likely create or worsen labor shortages—especially in sectors that already rely heavily on migrant workers. The size of the effect depends on the country, timing, and which types of immigration are halted.
Why it tends to cause shortages
•Demographics: Immigrants are disproportionately working-age. In aging, low-fertility countries, immigration is a main source of labor-force growth. Halting it shrinks the pipeline of new workers and raises dependency ratios.
•Sector concentration: Many industries lean heavily on migrant labor—agriculture and food processing, construction, hospitality, logistics, and caregiving/health support, as well as parts of STEM and healthcare. Cutting inflows quickly tightens these labor markets.
•Short-run rigidity: Raising wages and recruiting domestically helps but often can’t fill gaps fast due to training lags, licensing, geographic mismatch, and working conditions. The near-term result is unfilled vacancies, delayed projects, reduced output, and higher prices.
•Long-run adjustment limits: Firms can automate, reorganize, or relocate, and governments can boost training and participation (e.g., childcare for parents, upskilling, older-worker retention). These help but take years, and some roles (especially in-person care and many services) are hard to automate or offshore.
What evidence suggests
•Natural experiments (e.g., post-Brexit UK, US state crackdowns, the end of certain guest-worker programs) show immediate shortages in agriculture, hospitality, construction, and trucking, with some wage increases but also production cuts, higher costs, and business closures until partial policy reversals or workarounds.
•Countries with tight immigration (e.g., Japan) have faced chronic shortages in care, construction, and services despite rising wages and expanded automation, prompting gradual relaxation of entry rules.
•Where slack is high (recessions, regions with elevated unemployment), halting immigration may have smaller short-run effects, but aging still bites over time.
Possible offsets if immigration is curtailed
•Improve pay and conditions in shortage sectors; streamline licensing and recognition of credentials.
•Invest in training, apprenticeships, and faster pathways into high-need roles.
•Expand childcare, eldercare, and flexible work to raise participation, especially among women and older workers.
•Support housing and transport to widen feasible commutes.
•Targeted automation and process redesign; limited seasonal or sector-specific visas even if general immigration is restricted.
Bottom line: With current demographics and sectoral dependencies, stopping immigration would likely intensify labor shortages for several years and in some places persistently, unless paired with strong, sustained measures to boost domestic labor supply and productivity.
If you share the country and which immigration categories you mean (e.g., seasonal, low-skill, high-skill, students, family), I can give a more tailored estimate.