Skip to Content
Streetsblog USA home
Streetsblog USA home
Log In
Cars

Transport Economist Challenges Claim That ‘VMT Causes Growth’

The claim to a link between economic growth and vehicle mileage -- that, in other words, auto travel is essential to keeping U.S. productivity high -- remains controversial and much-debated in transportation policy circles.

One notable recent flare-up in that debate took place on National Journal's blog after road lobbyist Greg Cohen, referring to an October paper [PDF] released by the Cascade Policy Institute, contended that "it's not simply a correlation but VMT actually causes economic growth."

Now economist Todd Litman, founder of the Victoria Transport Policy Institute, has taken direct aim at the mileage-growth arguments made by Cascade's Randall Pozdena. In a paper [PDF] prepared for next week's Transportation Research Board conference in D.C., Litman charges that Pozdena's research "misrepesents" the relationship between prosperity and VMT "in important ways."

Litman questions Pozdena's conclusion, based on the below chart, that "increasing a country's income by 10 percent appears to increase its use of energy by the same percentage."

vtpi_2.png(Chart: VTPI/Litman)

Note that Pozdena equates a per-capita mileage in poorer nations with a per-capita mileage increase in richer ones, despite data showing that growth in car travel slows markedly once individuals reach a certain income level. Moreover, Litman notes, America and Norway end up close together on Pozdena's graph even though "Norwegians actually consume about half as much fuel per capita as U.S. residents."

Looking exclusively at developed nations -- specifically, the United States -- Litman found that per-capita productivity and VMT were negatively correlated. Check out his graph of the state-by-state trend below:

vtpi_1.png(Chart: VTPI/Litman)

By contrast, Litman found a positive correlation between per-capita productivity and fuel prices, suggesting that political opposition to gas-tax increases, motivated by fear of impeding economic growth, may be misguided.

But it's his takedown of Pozdena, using a truism that many remember from elementary statistics class, which packs the most punch. (Incidentally, the Cascade paper does argue in favor of one progressive transportation policy: congestion pricing, which it says may have a positive "economic footprint.")

Stay in touch

Sign up for our free newsletter

More from Streetsblog USA

Tuesday’s Headlines Are a Sanctuary

The Trump administration's latest threat would withhold funding from many big-city transit agencies and transportation projects in some blue states with "sanctuary" policies on immigration.

February 4, 2025

This Automaker Is Attacking Sustainable Transportation Even More Than You Think

The world's largest automaker has been ramping up spending to put climate change deniers in Congress, and crushing support for all kinds of sustainable modes in the process.

February 4, 2025

Op-Ed: How Transit Agencies Are Tackling America’s Public Bathroom Crisis

Lack of public restrooms can be a barrier to using transit — and a devastating problem for those who have no choice but to ride. This company is trying to solve the problem.

February 4, 2025

Monday’s Headlines Question Sprawl

Do Americans really want to live in car-centric suburbs, or are they forced to because that's where most of the housing is built?

February 3, 2025

Why Trump’s DOT is Promising More Money to States With Higher Birth Rates

Supporting American families in the transportation realm doesn't mean giving low-population red states more money for highways — even if a new DOT memo suggests that's exactly what they'll do.

February 2, 2025
See all posts