Young people are a nation’s greatest asset. As societies grow older, youth are relied upon to enter work, pay taxes and rear the next generation. But in an international labour market, talent retention is hard work for governments let alone businesses.

In the EU’s single market, it is particularly cut-throat. Many southern and eastern European economies — including Portugal, Italy, Poland and Romania — often see their youngest and most educated up sticks for the bloc’s more prosperous, and higher paying, northern economies. Plenty have not returned, hollowing out economies back home. The brain drain is, according to former Italian prime minister Enrico Letta, the “dark side” of the EU’s freedom of movement.

Last week, Portugal decided to take matters into its own hands. The minority government of Prime Minister Luís Montenegro unveiled an imaginative budget proposal to turn the country into a low-tax haven for young adults, offering a decade of tax breaks to those starting their careers. Under the plan, those aged 35 and under who earn up to €28,000 would pay no income tax for the first year. Tax relief would then be tapered over the next 10 years. Foreigners would also be able to benefit.