I think there is a host of factors to keep in mind about the nations in question. These nations (good health care, slow population growth) [1] tend to be highl

I think there is a host of factors to keep in mind about the nations in question. These nations (good health care, slow population growth) [1] tend to be highly developed countries [2], with relatively high average education of its citizens [3] and high life expectancy [4]. Many of them also have high social equality and high cost of living because of higher taxation (e.g. the cost of social programs and universal healthcare) [5]. [1]: http://en.wikipedia.org/wiki/List_of_countries_by_population_growth_rate http://en.wikipedia.org/wiki/List_of_countries_by_population... [2]: http://en.wikipedia.org/wiki/List_of_countries_by_Human_Development_Index http://en.wikipedia.org/wiki/List_of_countries_by_Human_Deve... [3]: http://en.wikipedia.org/wiki/Education_Index http://en.wikipedia.org/wiki/Education_Index [4]: http://en.wikipedia.org/wiki/List_of_countries_by_life_expectancy http://en.wikipedia.org/wiki/List_of_countries_by_life_expec... [5]: http://en.wikipedia.org/wiki/List_of_countries_by_inequality-adjusted_HDI http://en.wikipedia.org/wiki/List_of_countries_by_inequality...