Actually I forgot the perhaps most crucial point. Very few people are in unions who work as software developers. So it doesn't really make logical sense to make

Actually I forgot the perhaps most crucial point. Very few people are in unions who work as software developers. So it doesn't really make logical sense to make conclusions about software developer salaries based on unionization rate in the rest of the country. Engineers and software developers are if anything members of what could be more called trade groups. These groups don't negotiate or push for salaries on behalf of members, nor do they do things like organize strikes. To test you hypothesis I think you have to look at several countries in Europe at similar GDP number and compare salaries. Then you'd have to compare between those of different GDP numbers and see whether GDP or unionization rate correlates most with salaries. I got to point out however that such a task is momentously difficult, because differences in how things are recorded and rated. As an example I just remembered several other factors in addition to the previous mention that I forgot. 1) The salary quoted in Norway, is the money workers get after special income tax is deducted by the employer. This is about 14%. So a 65k salary is more like 75k if you consider this tax. 2) High living expenses in Norway is heavily influenced by a very high VAT tax of 25%. Sure that doesn't mean the money is suddenly in your pocket but it means it doesn't just disappear. It goes to cover extensive welfare services, which e.g. Americans would have to pay for out of pocket. In essence it is hard to compare very high tax regimes with extensive welfare benefits to one with low taxes and few benefits.