AS statistics released on February 26th revealed that net migration to Britain in the year to September 2014 was again at a higher level than when David Cameron, the Conservative prime minister, came to power in 2010, new research claims that Britain has suffered a net loss of numeracy as a result of all this immigration. John Jerrim of the Institute of Education at University College London, has produced what he calls the first quantitative look at the skills of people who move into and out of Britain.

Mr Jerrim analysed the OECD’s Programme for International Assessment of Adult Competencies, which covers two dozen countries and assesses the skills of adult populations. He measured the quality of education of migrants from those countries who came to Britain between 1964 to 2011. Focusing on the numeracy scores that are divided into quartiles, Britain lost 684,000 highly skilled people in those years, but this was cancelled out by an equal number of highly skilled immigrants coming in. In addition though, Britain also took in a large number of immigrants with lower numerical skills. The result was that almost four times more immigrants came from the lowest quartile compared with the highest. The study determined that Britain added 2.4 million people with numeracy skills in the lower three quartiles during that time.

Native Britons, or “stayers” as Mr Jerrim calls them, have similar numeracy test scores to British emigrants (at 267 and 268 points respectively). The average test score for immigrants was a lowly 234 points.

According to the ONS data, of the more than 600,000 immigrants who arrived in Britain in the past year, almost half came from outside Europe, which our chart suggests would increase the population with lower numeracy levels. In the digital age numeracy is a key skill and increasing the stock of the population that possess these skills is important. Britain seems to be doing the opposite.

The countries that benefit most from British emigrants with the highest numerical abilities are those that have the tightest entry requirements. Australia, Canada and the United States took in twice as many who were ranked in the top quartile compared with the lower three quartiles. For European countries the pattern is either the reverse or is flat.

As for those highly numerate Britons who move abroad, they generally earn more and report better health, but the extra wealth comes at the expense of working longer hours. According to Mr Jerrim’s research, the average expat clocked some 55 hours per week compared with just 44 for people in Britain. Working fewer hours and having your population’s general numeracy lowered by immigration might not be the best way for Britain to create a dynamic, growing economy.