I don't think the subsidy is required. The net deficit is small.

Some Swedish regions also have a net deficit relative to other Swedish regions, but that doesn't mean that they don't work out economically. After all, not all economic activity in region is taxed there. A firm in Örnsköldsvik pays their taxes to the Swedish government, and then the Swedish government distributes part back to the region.

It's around 600 million USD per year, on 56836 people. Around $1000 per head. But GDP per capita is $58,498.