Income tax reform has become a hot topic in both the United States and
Canada. Over the past few years, a variety of proposals have been adv
anced for the replacement of the current income tax system and most pr
oposals involve a compression of the multi-rate structure into a singl
e rate and a shift to some form of consumption tax base. Flat taxes ar
e advocated on the belief that they will provide a strong stimulus to
investment, employment and output. Their supporters are convinced that
the economic benefits are sufficiently large to make everyone better
off, therefore there is no need to be concerned about the distribution
al effects of flat taxes. However, the claims about potentially large
efficiency gains from flat taxes are not supported by research. Evalua
ting the effects of a consumption-base flat tax of the type proposed b
y Hall and Rabushka is one of the main purposes of the paper. Using a
microdata set for Canada, which allows identifying taxpayers by both i
ncome level and family type, we show that flat taxes not only increase
income inequality but also have important horizontal equity implicati
ons. We argue that a full debate on income tax reform requires a detai
led evaluation of both polar alternatives to the current hybrid income
tax: a move to a consumption base and a move to a comprehensive incom
e tax. Toward that end, we have performed a simulation which estimates
the distributional effects of a comprehensive income base with across
the board rate reductions in order to maintain revenue-neutrality. We
show that this option has advantages over the consumption-base flat t
ax in terms of both vertical and horizontal equity.