A move towards a non-uniform indirect tax structure may result in some
vertical redistribution. It will also lead to a different treatment o
f households with the same total expenditures but with different prefe
rences. To evaluate the social desirability of such rate differentiati
on we introduce a distinction between needs (for which individuals are
not responsible) and tastes (for which they are). Vile show some empi
rical results for Belgium, obtained with the microsimulation program A
STER. In these calculations we compare the actual Belgian system of in
direct taxes with a simpler structure with only two rates. (C) 1997 El
sevier Science B.V.