If there is a lesson from the latest Scottish population statistics, published yesterday, it is that Scotland needs its immigrants as much as they need us. Ever since Scotland's population first reached 5,000,000 in 1939, it has remained relatively stable. It is the make-up of that figure that has changed dramatically. Take 1950, a year when the tally of inhabitants was close to the latest total of 5,116,900. Today, more than 382,000 people in Scotland are 75 or over, while the number of those under 20, whose taxes and National Insurance contributions will be required to support them, is only 1,200,000. The equivalent figures for 1950 were fewer than 163,000 over-75s and more than 1,600,000 under-20s. It is an issue that First Minister Jack McConnell once described as the biggest single challenge facing Scotland.

We hear less about "the demographic timebomb" now than four years ago, when the registrar-general predicted the population would slump below the psychologically significant threshold of 5,000,000 by 2009. In the event, the population has risen each year since 2002. Two factors are responsible for this change. The most significant is the net inflow of predominantly young people coming to Scotland from both other areas of the UK and overseas, particularly the accession countries of the European Union. And, for the first time in many years, the number of births is edging up, while there are fewer deaths, thanks to advances in medical care. As a result, the gap between the two narrowed to just 300 last year. The figures do not tell us how many of these babies were born into immigrant families, though anecdotal evidence suggests that this is a factor in Scotland's recovering birthrate. Scotland's demographic timebomb may not have been defused but, as suggested in The Herald today, it has been "recalibrated".

However, we need to take account of these changes in the planning and provision of services. Many are already experiencing difficulties accessing decent affordable housing. If immigrant families are prepared to stay and put down roots, this has implications for everything from midwifery services and GP surgeries to school building and the recruitment of social workers. They deserve it. In general, immigration reduces wage and inflationary pressures and lowers unemployment, especially in the Scottish catering and hotel industries, where labour shortages are perennial. Immigrants are helping to rejuvenate towns and cities such as Fort William and Inverness. Their taxes and National Insurance contributions help to pay for public services and many also work in those services. If there is a failure in policy, it is in the comparatively small proportion of immigrants to Scotland working in "high-end" skilled jobs, especially business. A challenge to the next Holyrood administration will be to overcome the constraints of UK immigration policy and build on the modest success of the Fresh Talent initiative.