Yeah, it's from US data. In some places even $200/mo lets you live like a member of the upper class... I originally remember hearing the figure from a TED talk

Yeah, it's from US data. In some places even $200/mo lets you live like a member of the upper class... I originally remember hearing the figure from a TED talk ( here it is, highly recommended http://www.ted.com/talks/daniel_kahneman_the_riddle_of_experience_vs_memory.html http://www.ted.com/talks/daniel_kahneman_the_riddle_of_exper... ), and since then there have been a few other sources I can't remember right now.