Poor health outcomes appear to be an effect of economic inequality across a population. Nations and regions with greater economic inequality show poorer outcomes in life expectancy, mental health, drug abuse, obesity, educational performance, teenage birthrates, and ill health due to violence. On an international level, there is a positive correlation between developed countries with high economic equality and longevity. This is unrelated to average income per capita in wealthy nations. Economic gain only impacts life expectancy to a great degree in countries in which the mean per capita annual income is less than approximately $25,000.