In ten years’ time, there’s a good chance that the main concern in the western world will be the threat of population collapse. Fertility rates are falling everywhere and no government has found a way of reversing the trend. Plenty have tried. South Korea has so far spent $200 billion on tax breaks and lowering childcare costs and has succeeded only in beating its own record for the world’s lowest birth rate, year after year. In Italy, the situation is close to a crisis, and in France it’s not much better.

If this continues, the welfare state model, which depends on a decent worker-to–pensioner ratio, will collapse. There will not be enough tax revenue to finance pensions. A recent study in Italy showed that for every pensioner there are three people of working age, but by 2050 the ratio is projected to be closer to 1:1. The promise of a decent state pension would have to be withdrawn.

Japan’s Prime Minister refers to his country’s falling birth rate as an existential threat

Japan’s Prime Minister Fumio Kishida refers to his country’s falling birth rate as an existential threat. Giorgia Meloni says the same in Italy. For Marine Le Pen, a plan to increase the birth rate is part of her economic policy. The ‘increase in childless families’ is lamented by the AfD in Germany. This is likely to be a theme in the European parliament this year because in almost every country in Europe the working–age population has already started to decrease. This decline is expected only to accelerate.

This is not the case, however, in Britain. We learned this week that our working-age population is projected to keep rising. The figures were greeted with dismay, viewed as a result of out-of-control immigration. But which is the worse problem to have – too many people or too few? As South Korea has found out, no amount of panicked policy initiatives have succeeded in encouraging couples to have more children. As countries become richer, people choose to have smaller families or none at all.

Newcomers to the UK tend to have larger families, which is the main factor in maintaining our birth rate. Almost a third of all British babies are born to immigrant mothers. In London, it’s closer to 60 per cent. This has not prompted the country to come apart at the seams. Instead, we have created a multi–faith society whose cohesiveness is envied by much of Europe.

Some European populists advance the idea of a ‘great replacement’ plot by political masters to deliberately swap natives for lower–paid, more biddable migrants. But another explanation is that we now live in a world where people are on the move. Every day, 1,400 people emigrate from Britain and 3,200 newcomers arrive. Is this a great replacement – or the demographic response to a globalised world?

The problems arise when more people leave than arrive: a decline in population numbers is what brings crisis. Glasgow’s Herald newspaper has this week highlighted the plight of the Scottish Highlands, which it is calling the ‘new Highland clearances’. The exodus of young people, to either move abroad or elsewhere in the UK, has been going on for generations but is now reaching crisis point. While the London-based press frets about too many arrivals, there’s a clear opportunity for tax breaks or other financial incentives to persuade more people to settle in this beautiful corner of the world.

The UK is in a bind. A failure to address the welfare crisis – with 5.5 million on out-of-work benefits during a worker shortage – is drawing in a million migrants a year. This puts pressure on housing, due to the inability of the government to fix a broken system controlled by a small cabal of housebuilders and an ocean of red tape. The best way of lowering immigration is to have a welfare, tax and benefits programme that matches up jobless Britons with the vacancies in their areas.

Welfare reform is a huge undertaking, fraught with political risk. The Conservatives are not tackling it with any urgency. Labour does not fancy the task either, which is perhaps why it does not acknowledge the scale of the out-of-work benefits problem (18 per cent in Manchester, 20 per cent in Glasgow and Liverpool, 25 per cent in Blackpool). The inability to mobilise a national workforce will suck in others from abroad, as well as force up welfare costs and taxes.

But this will remedy itself: the sheer cost of the 4,000 a day who claim sickness benefits will bankrupt the next government. The need to address the problem is urgent, if politically painful. For countries such as Japan and Korea, there is no easy remedy to population loss.

The current high number of immigrants to the UK – many of them highly skilled people who are more likely to work and pay taxes than native Britons – nevertheless poses challenges. We need to build more homes and manage integration better, but these are issues that arise as a result of the country’s success. Compared with the crisis of working-age population decline in the rest of Europe, there are worse problems to have.