Unexpectedly Intriguing!
17 August 2009

Taxpayer Cash for Clunkers! Part of the attraction of the government's "Cash for Clunkers" taxpayer-financed subsidy for new car purchases is the claim that by replacing gas guzzling vehicles with newer, more fuel-efficient ones will greatly benefit the environment.

But will it really? How long might it take for taxpayers to get to enjoy the "green" benefit for the $4,500 tax credit they're being required to provide?

Clunker! Environmental economists like Matt Kahn ask questions like these and, fortunately for us, also work out the math to answer them! Our tool below is based upon his math and will answer the question of how long taxpayers will have to wait to get their money's worth of green benefits from the new vehicles acquired through the "Cash for Clunkers" trade-in program in the form of reduced carbon emissions from operating the vehicles.

Just enter the indicated data in the tool below. While most of the data is easily obtainable, the data related to carbon dioxide may not be. The EPA's estimate of 19.4 lbs per gallon is what we've entered for the amount of CO2 produce per gallon of fuel consumed (HT: Michael Roberts). Meanwhile, the cost of CO2 per ton in the calculation refers to the marginal social cost of an additional ton of carbon dioxide, which is subject to debate. Currently, the cost of a ton of CO2 in Europe is roughly $19 per metric ton (or $17.24 per U.S. short ton), but many argue that value doesn't incorporate the full "social" cost. We've used Matt's estimate of $35 per ton in the tool below for that figure, but you're more than welcome to change it!

"Clunker" Data
Input Data Values
Average Miles Driven per Year ("Clunker" Vehicle)
"Clunker" Fuel Economy [Miles per Gallon]
New Vehicle Data
Average Miles Driven per Year ("Green" Vehicle)
"Green" Vehicle Fuel Economy [Miles per Gallon]
"Cash for Clunkers" Taxpayer Subsidy Data
Amount of Tax Credit Provided by U.S. Taxpayers per "Clunker" Trade-In
Carbon Dioxide Emission Data
Amount of CO2 Produced per Gallon of Fuel [lbs per Gallon]
Cost of CO2 per Ton [$USD]

Clunker vs Green Vehicle Costs
Calculated Results Values
Annual Cost of CO2 Produced by the "Clunker" Vehicle
Annual Cost of CO2 Produced by the "Green" Vehicle
Difference Between "Green" and "Clunker" Costs [Positive if Savings]
Years to "Pay Back" Taxpayer with Lower CO2 Emissions

Using the default numbers, we find that it takes a very long time for taxpayers to get their money's worth for what they were required to spend to support the "Cash for Clunkers" program. At 26.5 years, the time needed to obtain the perceived benefits of reduced CO2 emissions will very likely outstrip the useful life of the new "green" vehicle, suggesting that taxpayers will never realize a positive environmental return on the $4,500 they provided to subsidize the new car sale.

Other Comments

In the tool above, we've incorporated the assumption that the money provided by U.S. taxpayers to those trading in their "clunkers" is at a 0% rate of interest. As Matt notes, if the interest rate is positive, it significantly increases the amount of time the taxpayer must wait to get a positive return on their "investment" in putting a greener vehicle on the road in place of a less fuel-efficient one.

We'll also note that greater fuel efficiency tends to increase the amount of driving, which would also act to increase the amount of time required to obtain a "green" payback. While we've set the annual miles driven for each type of vehicle to be the same in the tool above, you can change the data to account for this effect.

On the other side of the balance, there may be other benefits that may be realized beyond CO2 reduction from operating a more fuel-efficient vehicle, such as the net reduction of other emissions that may reduce the time needed for taxpayers to get a positive benefit from subsidizing new vehicle sales through this government program.

Labels: , , ,

About Political Calculations

Welcome to the blogosphere's toolchest! Here, unlike other blogs dedicated to analyzing current events, we create easy-to-use, simple tools to do the math related to them so you can get in on the action too! If you would like to learn more about these tools, or if you would like to contribute ideas to develop for this blog, please e-mail us at:

ironman at politicalcalculations.com

Thanks in advance!

Recent Posts

Stock Charts and News

Most Popular Posts
Quick Index

Site Data

This site is primarily powered by:

This page is powered by Blogger. Isn't yours?

CSS Validation

Valid CSS!

RSS Site Feed

AddThis Feed Button


The tools on this site are built using JavaScript. If you would like to learn more, one of the best free resources on the web is available at W3Schools.com.

Other Cool Resources

Blog Roll

Market Links

Useful Election Data
Charities We Support
Shopping Guides
Recommended Reading
Recently Shopped

Seeking Alpha Certified

Legal Disclaimer

Materials on this website are published by Political Calculations to provide visitors with free information and insights regarding the incentives created by the laws and policies described. However, this website is not designed for the purpose of providing legal, medical or financial advice to individuals. Visitors should not rely upon information on this website as a substitute for personal legal, medical or financial advice. While we make every effort to provide accurate website information, laws can change and inaccuracies happen despite our best efforts. If you have an individual problem, you should seek advice from a licensed professional in your state, i.e., by a competent authority with specialized knowledge who can apply it to the particular circumstances of your case.