0423 GMT July 20, 2019
But a report from the United Nations (UN) warned that once migrants have arrived, host countries often fail to make use of their talents, BBC reported.
The UN has published an analysis showing only 30 percent of migrants with degrees are in graduate-level jobs.
It comes ahead of a UN convention this year that aims to make it easier for migrants to use their skills and work experience in their new countries.
"Stories of immigrant doctors who are cab drivers or surgeons who are flipping burgers bring to light how much potential is being wasted the world over," said Ita Sheehy, an education adviser with the UN High Commission for Refugees (UNHCR).
As well as being frustrating for ambitious migrants, the UN said, it is wasteful for economies to have high-skilled people in low-skilled jobs.
Evidence of skills
The analysis, jointly produced by the UNHCR, UNESCO's global education monitoring report and the Education Above All charity, said that the biggest barrier can often be the lack of international recognition for qualifications.
Even though someone might have advanced professional qualifications in their home country, if there is no system of mutual recognition, they are effectively treated as if those skills did not exist.
About three-quarters of migrants are in countries without an agreement on recognizing qualifications from the countries that they have left.
"Some migrants and refugees find the procedures for getting their qualifications recognized so complex that they cannot find work at all," said Sheehy.
This is a global problem, affecting people displaced by conflict across the Middle East, Asia and in Africa, as well as those arriving in Western Europe and North America.
It is particularly bad for refugees or those escaping violence, who might arrive with little documentation or evidence of qualifications.
"When fleeing a conflict, packing a diploma is likely not to be top of your mind," said Manos Antoninis, the director of UNESCO's global education monitoring report.
Lack of recognition
It is also an issue for mobile professional workers, who might study and train in one country but then later move to live and work elsewhere.
In 2019, the UN plans to introduce a "global convention on the recognition of higher education qualifications", intended to make it easier for people to show the value of their qualifications if they move to another country.
It promises ‘fair, transparent and nondiscriminatory’ approaches to help people get their qualifications assessed by education authorities in another country.
But at present it is very much a patchwork quilt of national regulations — and even when there are agreements in place, this can be more in theory than in practice.
An international agreement from more than 20 years ago promised a framework for recognizing qualifications — but the UN report said that most of the signatories have never put it in place.
The US is highlighted as a place where skilled migrants are particularly likely to be stuck in low-paid jobs.
And in Southeast Asia, a reciprocal arrangement meant to recognize professional qualifications has rarely been used, said the report.
But it commends efforts in Germany and Norway to recognize the qualifications and work skills of those arriving.
Unable to use skills
Even in jobs where there are staff shortages, it can sometimes be difficult for migrants to use their expertise.
In England, there has been a prolonged teacher recruitment problem.
But Beata Pawlak, a secondary school teacher from Poland, said she found it difficult to find work as a teacher or teaching assistant when she moved to live in London.
She has a postgraduate degree and English-language qualifications and 16 years of teaching experience in Poland but has struggled to get into teaching in London.
Instead, she became a nanny and said many other fellow professionals had ended up in jobs such as cleaning or in other non-graduate work.
"I know the work is below my skill level but in the end decided it wasn't worth the effort of applying again and again for teaching work. It was humiliating," she said.