You're right. I wasn't thinking about crossing borders when I wrote that. Within the US, it's essentially true. Comparing US to Europe or anywhere else and it's all over the map.
I guess that's just another variable to throw in when working on your arbitrage strategy. Personally, I'd opt to take that contract job in Oslo if it were an option. Given how much they charged me for beer when I was there, I can only assume the wages must be nice and high!
Wages in Norway are quite flat compared to the US. The low end wages are much higher and the high wages are lower. If you're making $20-30k in the US you'll earn a lot more in Norway. If you're making around $100k you'll probably make the same. If you're earning over $200K you'll probably make less.
Wages usually depend on supply and demand in the local market, unless your niche is so specialized you personally compete globally (in which case you're probably earning a lot more than $100K). I'm not intimately familiar with Norway, but I'd bet heavily that a $100K job in the Bay Area probably would not translate to a 570K NOK salary. Healthcare, pension and cost of living differences also make it hard to compare.
I guess that's just another variable to throw in when working on your arbitrage strategy. Personally, I'd opt to take that contract job in Oslo if it were an option. Given how much they charged me for beer when I was there, I can only assume the wages must be nice and high!