Atkinson and Stiglitz show that with weakly separability, differential commodity taxes are unnecessary given an optimal nonlinear income tax. Deaton showed that with an optimal linear progressive income tax, commodity taxes are superfluous under weakly separable and linear Engel curves. Using...

This paper shows that the combination of habit formation - present consumption creating additional consumption needs in the future - and myopia may explain why some retirees are forced to 'unretire', i.e., unexpectedly return to work. It also shows that when myopia about habit formation leads to...