For years, critics of the Optional Practical Training (OPT) programme have argued that allowing international STEM graduates to work in the United States takes jobs away from American workers. But a study by the National Foundation for American Policy (NFAP) challenges that narrative, finding no evidence that foreign graduates participating in the programme reduce employment opportunities for US workers.Also Read| US OPT programme explained: How Trump's $100,000 fee could hit international studentsThe findings come as the Trump administration has made legal immigration more restrictive through measures including sharply higher H-1B visa fees, tougher enforcement and proposals affecting work authorisation for international students.Since returning to office, Donald Trump has steadily tightened pathways for foreign workers and international students. His administration has imposed a $100,000 fee on most new H-1B petitions subject to the annual cap, proposed extending additional H-1B and L-1 filing fees to visa extension applications for certain employers, expanded immigration enforcement, and signalled plans to overhaul the Optional Practical Training (OPT) programme that allows international graduates to work in the US after completing their studies. The administration has also stepped up scrutiny of student visas and work authorisation, arguing that immigration policies should better protect American workers.Against this backdrop, the NFAP study challenges one of the central assumptions underpinning such policies—that foreign STEM graduates displace American workers. According to the report, the evidence does not support that claim.Small footprint, big debateDespite the attention the programme receives, the report says OPT participants make up only a small fraction of the US STEM workforce.In 2016, foreign graduates on post-completion OPT or STEM OPT extensions accounted for less than 1% of workers with a bachelor's degree in a STEM field and about 2.5% of workers in STEM occupations with at least a bachelor's degree. Among new graduates, they represented less than 1% of all bachelor's STEM graduates, under 10% of master's graduates and under 15% of PhD graduates.The report says the programme's relatively small footprint makes it difficult to support claims that it has a widespread impact on employment opportunities for American workers.Hiring where the gaps areRather than replacing US workers, employers appear to use the programme to fill shortages, according to the analysis.The study found that the relative number of foreign students approved for OPT was negatively related to unemployment among comparable US STEM workers. In other words, employers were more likely to hire international graduates in places and fields where American STEM workers were scarcer.The report describes the programme as acting like a "safety valve" for tight labour markets by providing employers with an additional source of skilled workers.Also Read| Trump's new student visa rule could cost US economy up to $400 billion a yearMore foreign graduates, lower unemployment?The researchers examined data across states, metropolitan areas and STEM disciplines and found a consistent pattern: regions with relatively more foreign graduates working through OPT generally had lower unemployment rates among American STEM workers.The report does not claim that OPT directly lowers unemployment. However, it says the findings do not support the argument that the programme harms employment prospects for US workers. Instead, the relationship suggests employers rely on OPT when labour markets are tight.More than an immigration programmeThe report argues that OPT serves a broader economic purpose than simply allowing graduates to remain in the country temporarily.It says the programme helps employers evaluate international graduates before sponsoring them for H-1B visas, while also making US universities more attractive to overseas students by offering post-study work opportunities. The report further notes that previous research has linked foreign-born STEM workers with higher innovation, productivity and patenting.Also Read| Bill introduced in US Senate seeks 3-year pause on H-1B visas, codify $100,000 feeThe evidence, not the rhetoricThe report concludes that there is no evidence foreign students participating in the STEM OPT programme reduce job opportunities for American workers. Instead, it concludes that employers appear to turn to OPT when domestic STEM talent is scarce, suggesting the programme functions as a labour-market safety valve rather than a substitute for American workers.