Stopping all immigration would likely cause labor shortages in most developed countries, but the size and timing would depend on the country, the industries involved, and how quickly it was stopped.
Here is how economists generally view it:
1. Why it would cause shortages
Most developed economies rely on immigration for labor force growth:
•Population and demographics: In the US, Canada, UK, and most of the EU, the birth rate is below replacement level of 2.1 children per woman. Without immigration, the overall population ages and the workforce shrinks as more people retire than enter the workforce.
•Share of workforce: In the US, foreign-born workers make up about 18-19% of the labor force. In sectors like agriculture, construction, hospitality, home health care, and STEM they make up an even larger share.
•Jobs with domestic recruitment challenges: Agriculture, meatpacking, farm labor, housekeeping, construction labor, trucking, and elder care often have high turnover, physical demands, or seasonal needs that employers have historically struggled to fill with native-born workers at current wages.
If immigration stopped completely and abruptly, those sectors would be the first to see acute shortages. Over 10-20 years, the effect would be broader - fewer workers overall to support growth, pay taxes, and fill jobs created by retirements.
Examples often cited are Japan and South Korea, which have very low immigration and are now experiencing persistent labor shortages and economic contraction due to an aging and shrinking workforce.
2. What would mitigate or offset it
Stopping or reducing immigration would also create other economic adjustments:
•Wages and participation: A tighter labor supply tends to push wages up, which can draw more domestic workers into the labor force, including people who are currently not working or working part-time.
•Automation and productivity: Employers may invest more in automation, technology, and labor-saving processes when labor is scarce and more expensive.
•Training and mobility: More resources may go to training domestic workers for healthcare, skilled trades, and technical roles.
3. Short-term vs. Long-term
•Short-term: An immediate stop would likely cause disruption and shortages in immigrant-heavy industries, leading to higher costs, delays, and reduced output in those sectors.
•Long-term: The overall labor force would grow more slowly or shrink, which most economic models project would lower GDP growth. Whether that is perceived as a "shortage" or just a smaller economy with higher wages depends on productivity growth and domestic workforce participation.
In summary, most labor economists agree that immigration is currently a major source of net labor force growth in developed economies. Stopping it entirely would not cause an instant shortage in every industry, but it would create significant shortages in specific sectors quickly and a general shrinking of the available workforce over time.
If you tell me which country you are asking about, I can give you more specific data on which industries would be most affected.