[joisig]

Some part of the reason for this is that pretty much anybody who is owns a single-family home in Iceland outright and is otherwise mostly debt-free would count as a millionaire (in USD) these days, because housing has appreciated by ridiculous amounts in the last 20 years or so.

One of the reasons there are a lot of house-millionaires is because some of the oldest generations, who bought their homes before 1980 or so, took normal loans with fixed interest rates, just before massive inflation in the 80s. The decrease in value per krona in ten years starting 1980 was something like 99.7%, so the loans went pretty quickly to something indistinguishable from zero. Inflation-indexed loans have been the only type of housing loan you could get for most of the time since about 1981, and are still the norm. The effect around that time of transition was that the younger generations (next waves of house buyers after them) were saddled with a lot of the burden.

Source: I'm Icelandic.