Atheists as a whole are better educated and earn more money than people of faith, so that’s probably part of where the money comes from. Atheists as a whole make more money than agnostics (which is my own personal point of view, although I’m technically somewhere between Apathetic Agnostic and Secular Humanist).
Interestingly, atheists also tend to marry later, have fewer children, and are much less likely to get divorced (although comparable for believers who marry later and have similar education levels).
