In case you've missed it, there IS in fact a bit of an economic boom in northern Sweden, related to green technologies and energy-intensive activities. I guess it's most obvious in Skellefteå due to Northvolt, but that's not the only place. That's why SFT is one of very few Swedish airports that saw more traffic in 2023 than in 2019. (Of course, we can't rule out that there is a bit of a green tech bubble rather than a boom that will go on for ever, and that would cause some quite painful adjustments when it bursts, in terms of sunk investments and value losses in real estate.) Parallell to that, on a smaller scale, there are a number of towns in "central" Sweden with manufacturing activities which have shifted from ever-decreasing population to a more stable situation. (I was born in one of those places, so I check the numbers now and then.) Definitely a shift in outlook in some of those places, although not really a boom, and it doesn't show up in air traffic because you don't usually fly between those towns and the bigger cities, so it's less relevant for this forum.
Haven’t missed Skelleftea’s growth and heard all about the housing issues and more there. It with the electric battery/green tech stuff and other stuff in the north isn’t (yet at least) a big enough boom to make ARN into a lot more than ARN already is on the international flight scene. For comparison purposes, I think of the SFT area boom as sort of like the fracking and other energy related boom in the Dakotas in the US. It didn’t really amount to much for MSP’s ability to grow. Sure, MSP will have more international routes and carriers this year than before that boom, but the boom several hours to the north and west of MSP a dozen years back really didn’t move the dial for MSP then or ever since. Sort of the same way for ARN: you get a regional boom and you get some more short/mid-haul demand and maybe more leisure charters; but it’s not a sufficiently large and close enough boom involving a large enough flying population to change the dial for the business of the major airport/airline hub several hours away that is closest to it. Even if there is a sustainable strength to what is going on several hours north and west of ARN, just look at what Stavanger has meant for OSL as a hub over the years. OSL hasn’t been able to do much better business for international long-haul than ARN, and OSL has the benefit of lots of oil money accrued over the years and arguably a somewhat better geographic position than ARN for passenger and goods traffic destined to come in and continue on by air.
In some (hopefully distant) future when I am no longer around and everyone wants to escape to Stockholm or further north to avoid even too hot Denmark and rising sea levels flooding CPH and a bunch of places around Skane’s coast, then I can foresee Stockholm and ARN being more than CPH.