US president Donald Trump and the Republican party have made it a priority to scale back the H-1B and so-called “startup visa” programs in their push for an “America First” policy. Both programs have been put on notice for reform or effective elimination. On Aug. 2, Trump endorsed a proposal (paywall) to cut legal immigration in half within a decade and prevent American citizens and legal residents to bring family members into the country in favor of a merit-based system based on skills, education and language.

As Trump pursues policies shutting the door to more immigrants to the US, tech companies are getting the message, says online hiring platform Hired in a new study on global trends. US tech companies on the Hired platform are interviewing less foreign candidates, reports Hired, which has a marketplace of more than 10,000 participating companies and 1.5 million job seekers, and facilitated more than 175,000 interview requests and job offers. The survey findings are based on a survey of 362 tech workers based in the US (made up of product managers, software engineers, data scientists, and designers).

Hired compared the number of interview requests extended to foreign candidates in each quarter with those from the same period a year earlier. It found quarterly requests fell an average of 42% in 2017, and recruitment of US candidates held steady (Hired did not disclose the exact percent).

The report arrives in the middle of a raging debate: Is there really a shortage of skilled engineers and scientists in the US? The United States must mint 1 million more STEM professionals than it’s expected to produce during the next decade to maintain the country’s edge in science and technology, reported the President’s Council of Advisors on Science and Technology in 2016. That implies churning out 34% more graduates in fields like mathematics, engineering, science and other fields at a time when enrollment by US citizens is actually declining. Making up the difference, argue immigration advocates, means hiring the best from around the world.

Industry groups such as the Partnership for a New American Economy, representing companies such as Disney, promote this position. Critics accuse these US multi-national corporations of hyping up the shortage to justify visa programs for cheap, offshore temporary workers and students. A more nuanced answer, issued by the US Bureau of Labor Statistics in a 2016 labor market analysis, is that it depends.

A chronic shortage has persisted in some fields such as petroleum engineering, software development, and technical government fields (where citizenship is required). Yet there are plenty of physicists, biomedical engineers, and chemical engineers available in their respective fields. But indiscriminately cutting off the flow of talent to the US, rather than selectively reforming the system, could backfire by depressing economic growth and starving companies of talent to compete globally. It may even send the next Google somewhere else. Foreigners have founded more than half of America’s private start-ups valued at $1 billion dollars or more, according to a report by the National Foundation for American Policy (pdf), a non-partisan think tank. That share grows to 70% of so-called unicorns as of 2016 once companies with immigrants in key management or product roles are included.

Many of those potential founders may not stick around. Sixty percent of US-based technology workers Hired surveyed on its platform expect the Trump administration to harm the tech industry. A quarter are less likely to start a company in the US. Their top choice? One-third named Canada as their top choice, followed by Germany (12%), Asia (10%), and Australia (10%).

Update: The methodology for this study was updated with the most recent figures for the number of companies and job candidates on the Hired platform.