ON APRIL 18th Donald Trump is expected to sign an executive order that will tighten the screws on legal immigration. During his presidential campaign, he vowed to end the H-1B visa programme, which grants 85,000 skilled foreigners a year the right to live and work in the United States, and opens up a path to citizenship. He says such migrants undercut wages for the native-born. Although the new policy will not scrap H-1Bs entirely, it will allocate them on merit rather than by the current lottery system.

If implemented, this reform is likely to shift the pool of H-1B holders towards better-skilled—and higher-earning—foreign workers. The impact of such a change would be highly concentrated. H-1Bs are formally targeted at easing labour shortages and attracting talent in “specialty occupations”, such as medicine and computer science. However, the biggest users of them by far are Indian business-process outsourcing companies, which predominantly provide technology support to corporate back offices.

The range of salaries earned by H-1B holders is extremely wide. At the high end, it reaches well into the six figures; at the other extreme, it falls below the programme’s nominal minimum wage of $60,000 a year, thanks to exceptions granted to academics and the like. However, according to an analysis by Théo Négri of jobsintech.io, an employment website, the three largest Indian outsourcers—TCS, Wipro and Infosys—mostly limit their use of the visa to workers earning just above the salary floor. The median income of their H-1B employees was just $69,500, 40% less than the corresponding figure of $117,000 American tech giants pay to such staff. As a result, if Mr Trump’s policy led to a de facto increase in the minimum salary of merely $10,000, half of the Indian outsourcers’ H-1B workers would become ineligible.

The H-1B scheme has vocal defenders, particularly in the technology industry and among economists. They note that making it harder for American firms to bring in talent will entice them to relocate their operations abroad, and that H-1Bs have brought numerous successful entrepreneurs to the United States, such as Mike Krieger, a founder of Instagram. But even some supporters of the programme retort that the next Mr Krieger is unlikely to be lurking among the thousands of back-office staff brought in by the outsourcers. As long as the total number of H-1Bs remains capped, eliminating workers with middling skills might actually free up slots for more enterprising immigrants.