Migrant workers generally earn nearly 13% less than national workers in high income countries, though the gap can be as high as 42% in some jurisdictions, according to the latest research from the International Labour Organisation (ILO).
However, the ILO found the reverse in low- or middle-income countries, where migrant workers generally earned on average 17.3% more than local workers, as they tended to be "temporary high-skilled expatriates".
The ILO report entitled 'The migrant pay gap: Understanding wage differences between migrants and nationals' also reveals that the pay disadvantage experienced by migrant and national workers in some countries - including Ireland - has worsened since 2015.
The research suggests that the Covid-19 pandemic has had a greater health and economic impact on migrant workers, with "tens of millions" forced to return home after losing their employment - as many of their jobs are less amenable to teleworking.
"The crisis of which we do not yet have a complete picture may widen the labour market differences between migrant workers and nationals, which may in turn further deepen migrant pay gaps," the ILO stated.
The ILO found that women migrant workers face a "double wage penalty", both as migrants and as women.
"This is partly because migrant women workers represent a significant share of those in domestic work: 73% (or 8.45 million) of all migrant domestic workers around the world. In high-income countries, the pay gap between migrant care workers and non-migrant care workers is about 19%," the report said.
"The pay gap between male nationals and migrant women in high-income countries is estimated at nearly 21% per hour. This is higher than the gender pay gap (16%) in those countries."
Migrants in high-income countries are more likely to be in precarious work, with 27% on temporary contracts, and 15% working part-time.
They are also disproportionately represented in sectors like agriculture, fishing and forestry, and take up more jobs than nationals in industries like mining, quarrying, manufacturing, electricity, gas, water, and construction.
"Migrant workers often face inequality of treatment in the labour market, including with respect to wages, access to employment and training, conditions of work, social security, and trade union rights," said the Chief of the ILO Labour Migration Branch Michelle Leighton.
"They play a fundamental role in many economies. They cannot be considered as second-class citizens."
While the average pay differential in high-income countries was around 13%, the situation for migrants was significantly worse in some locations.
In Cyprus this year's pay gap was 42%, in Italy it stood at 30%, while Austria reported a differential of 25%.
In Finland the gap was lower than the international average of 13% at 11%.
In the EU as a whole, national workers earned on average 9% more than migrants in 2020 - though the ILO research indicates that the situation has deteriorated over the last five years.
In Ireland, the advantage experienced by national workers over migrants in 2015 was 19% - but by this year, it has risen to 21%.
This means a migrant worker doing the same job as a national worker is earning on average around a fifth less.
Over the same period, the pay gap in Italy rose from 27% in 2015 to 30% in 2020, with Portugal experiencing a rise from 25% to 29%.
The ILO report also identified a "skills mismatch", whereby migrants often end up in jobs that do not reflect their skill level or education.
"They are more likely to work in lower-skilled and low-paid jobs that do not match their education and skills, which may point to discrimination during the hiring process. Higher-educated migrant workers in high-income countries are also less likely to attain jobs in higher occupational categories," it noted.
The report cites the example of the United States, where the share of migrant workers with secondary school level education is 78% - but they only account for 35% of high- or semi-skilled jobs.
In Finland, where 98% of migrant workers had a secondary school education, just 50% were in high-or semi-skilled work.
"This reflects the fact that they have difficulties transferring their skills and experience across countries, in large part due to lack of systems that recognise the skills and qualifications of migrant workers," the ILO found.
The Director of Migrant Rights Centre Ieland, Edel McGinley, described the ILO report on the pay gap for migrant workers as "shocking", but said it came as no surprise.
She said that MRCI knew from their work that migrants are over-represented in essential but low paid work, where conditions of employment are often precarious, and are shaped by the labour market, labour migration policy and the work permit system.
She urged the Irish Government to take action to ensure that pay and terms and conditions are "equitable and fair for all workers".
"Many employers put profit above their workers and this needs to change. Migrant workers are an intrinsic part of the fabric of Ireland and must be valued as such," Ms McGinley said.
She cited MRCI's recent report into the experiences of meat factory workers, which she described as a sector where low pay is the norm, with very poor pay increases over prolonged period.
However, she added that as the ILO report showed, this was not limited to one sector, but was a widespread experience across the economy in areas including homecare, agri-food (meat, mushrooms, fruit and fishing) along with hospitality and cleaning.
"We are very concerned about the segmentation of the labour market and widespread discrimination within it. In tandem, the lack of recognition of past experience and qualifications by employers means that there are low levels of progression and low representation in managerial and supervisory roles," she concluded.