CHAPTER 6 SUPPLY, DEMAND, AND GOVERNMENT POLICIES 129
To analyze these proposals, we need to address a simple but subtle question:
When the government levies a tax on a good, who bears the burden of the tax? The
people buying the good? The people selling the good? Or, if buyers and sellers
share the tax burden, what determines how the burden is divided? Can the government
simply legislate the division of the burden, as the mayor is suggesting, or
is the division determined by more fundamental forces in the economy? Economists
use the term tax incidence to refer to these questions about the distribution
of a tax burden. As we will see, we can learn some surprising lessons about tax incidence
just by applying the tools of supply and demand.
HOW TAXES ON BUYERS AFFECT MARKET OUTCOMES
We first consider a tax levied on buyers of a good. Suppose, for instance, that our
local government passes a law requiring buyers of ice-cream cones to send $0.50 to
the government for each ice-cream cone they buy. How does this law affect the
buyers and sellers of ice cream? To answer this question, we can follow the three
steps in Chapter 4 for analyzing supply and demand: (1) We decide whether the
law affects the supply curve or demand curve. (2) We decide which way the curve
shifts. (3) We examine how the shift affects the equilibrium.
The initial impact of the tax is on the demand for ice cream. The supply curve
is not affected because, for any given price of ice cream, sellers have the same incentive
to provide ice cream to the market. By contrast, buyers now have to pay a
tax to the government (as well as the price to the sellers) whenever they buy ice
cream. Thus, the tax shifts the demand curve for ice cream.
The direction of the shift is easy to determine. Because the tax on buyers
makes buying ice cream less attractive, buyers demand a smaller quantity of ice
cream at every price. As a result, the demand curve shifts to the left (or, equivalently,
downward), as shown in Figure 6-6.