Correlations

Miguel Barrientos' IndexMundi allows you to plot correlations of several values... [IM Blog]

Migration and GDP per capita - slightly positive, indicating that wealthier countries have higher immigration rates (some interesting cause/effect arguments here)

Richer countries have lower infant mortality rates and have higher life expectancy and lower fertility and higher literacy and may not be getting richer(!) and lower unemployment and lower industrial production growth rate (!)