familiar regulations are direct controls—mandatory catalytic
converters, fuel-efficiency standards, and the like.
a. Given the discussion in the chapter, why do you think the
government opted for such direct controls?
b. Can you think of any indirect controls currently in use to
reduce automobile pollution?
c. Until 2015, the federal government was considering using
direct regulatory controls to reduce the emission of
greenhouse gases. Can you think of a political reason why
any government might prefer direct controls over either
emissions taxes or tradable emission permits?
9. The following identity shows the three essential components of
the world’s annual emissions of greenhouse gases:
a. Explain the meaning of the first component,
GHG/Energy.
b. Explain the meaning of the second component,
Energy/GDP.
c. Explain why world GDP is likely to continue growing
over time. How is this related to world population
growth?
d. Explain why the second term is likely to fall over time but
by less than the growth in world GDP.GHG= EnergyGHG ×EnergyGDP ×GDP