Despite the old saw that money can’t buy happiness, the two tend to be correlated. Up to about $75,000, the higher your income, the happier you tend to be.

Correlation, of course, does not equal causation. It’s quite possible that the connection between money and happiness is not a direct one. It’s hard to root out the causal mechanism because so many of the good things in life correlate with one another. Income, marriage, sobriety, health, and education all tend to coexist in the same people and communities.