Burning of fossil fuels emits carbon oxides into the atmosphere, which many scientists believe increase the rate at which the earth’s climate is warming. Gasoline emissions from internal combustion engines also produce volatile organic compounds (voc’s) which contribute to smog creation when air inversion conditions are present. Which of the following two approaches to reducing harmful auto emissions is likely to be more efficient in achieving a desired target level of emissions reduction from internal combustion engines? Explain your answer

a) Legislate that within 5 years all automobile manufacturers must meet some sharply higher minimum mileage standard averaged over all new vehicles sold by the manufacturer than is now customary in the industry or face heavy fines.

b) Raise the federal excise tax on gasoline sharply while reducing federal personal income tax rates such that the total amount of tax revenues collected by the federal government from all US households combined does not change. (Although of course the distribution of that overall tax burden across individual households will shift depending on household transportation choices).