Comment by ls612

Keynes had a key observation that if people like both consumption and leisure and have to trade them off against one another, that the income effect of getting richer will dominate the substitution effect between consumption and leisure, so people in richer societies will both work less and consume more. The exact number of hours worked is just a function of the elasticity of substitution between consumption and leisure which he incorrectly guessed (not having the methods back then to empirically estimate it).