Diener, E., &Biswas-Diener, R. (2002). Will money increase subjective well-being?. Social indicators research, 57(2), 119-169.
Four replicable findings have emerged regarding the relation between income and subjective well-being (SWB): 1. There are large correlations between the wealth of nations and the mean reports of SWB in them, 2. There are mostly small correlations between income and SWB within nations, although these correlations appear to be larger in poor nations, and the risk of unhappiness is much higher for poor people, ...