If you ask an economist about transport policy, it’s a certainty that they will mention congestion pricing at some point. It’s easy to see why. Currently, we manage our roads like a Soviet supermarket: access is rationed by queues rather than prices. As a result, we get inefficient outcomes.
The theoretical and empirical case for congestion pricing is strong. In places where it has been implemented, such as London and Stockholm, it has increased vehicle speeds, improved accessibility, cut pollution, and improved safety. Not bad.
Because congestion pricing works, it tends to become quite popular once people can see the results. Although a majority of Londoners and Stockholmians opposed tolls at the outset, around 70% of residents in both cities now support them. But all of this raises a question: why haven’t more cities implemented congestion pricing?
I was thinking about this when reading a pair of articles that David Roberts (Vox) recently wrote about carbon taxes – and why they may not necessarily be the best policy for preventing climate change. Many of the points that he raises are also relevant to a discussion of congestion pricing.
In the first article, Roberts discusses the benefits of carbon taxes (efficiency) and the problems associated with applying them to complex markets. He argues that:
Believing a single tool will accomplish everything requires seeing the economy as a frictionless machine, a spreadsheet, not what it is: a path-dependent accretion of past decisions and sunk costs, to be tweaked and unwound.
As a result, it may make more sense to intervene more directly in specific markets – say, by regulating coal-fired power plants out of existence or subsidising alternatives. The equivalent in the transport space would be to manage congestion by cobbling together a raft of policies that look unrelated at first glance – e.g. transformative investments in rapid transit and cycling, bus lanes or high-occupancy-toll lanes on more roads, and higher parking prices.
In the second article, Roberts addresses a more challenging issue: politics and the art of the possible. He argues that carbon taxes are seldom effective in practice due to several factors that make implementing them and raising the tax to an effective level a risky proposition. These include concerns about distributional impacts, or the degree to which poor people will bear the impact, and low willingness to pay to avoid harms. Both of these factors seem potentially relevant to congestion pricing as well.
Roberts points out that many of the policy recommendations made for carbon taxes are economically sensible but respond poorly to political constraints. For example:
Many conventional economists, along with some of the few conservatives who take climate policy seriously, favor a “tax shift”: using the carbon tax revenue to reduce other taxes, preferably “distortionary” taxes like payroll or income.
The idea is that you double your impact: You get less of what you don’t want (carbon) and more of what you do want (work) — more efficient markets on both sides. Harvard economist Greg Mankiw is a big proponent of this perspective, as is Bob Inglis, one of the few conservatives actively working on climate change policy.
The main thing to note about tax-shift schemes is that they address few of the political barriers facing carbon pricing.
A carbon/income tax swap would be doubly regressive — raising a regressive tax to lower a progressive one. Reducing payroll taxes might have a net progressive effect, but it is very difficult to imagine the politics working.
In the past, I’ve taken a similar view on congestion charges. I’ve argued that we shouldn’t raise money from tolls. Rather, the revenues should be distributed back to households, and especially low-income households who might be most adversely affected.
But, Roberts suggests, offering to return the revenues will not necessarily make carbon taxes (or congestion pricing, I suspect) popular with the public. Instead, a more popular approach might be to tax something bad – e.g. carbon emissions or road congestion – and reinvest the revenues in something good, like renewable energy or better transport choice:
On the 2014 National Surveys on Energy and Environment, a carbon tax with no specified revenue use polled poorly. But things changed when different uses of the revenue were offered alongside the tax.
USA Today describes the results:
[A] different picture emerges when survey participants are asked about three possible uses of the tax revenue. If used to fund programs for renewable power like solar and wind, 60% back the tax overall, including 51% of Republicans, 54% of Independents and 70% of Democrats.
A smaller majority supports a tax if the revenue is returned to them via a rebate check. While 56% overall favor this idea, support ranges from 43% for Republicans to 52% for Independents and 65% for Democrats.
The third option — using the tax revenue to reduce the massive U.S. fiscal deficit — is not popular with any political group. It is opposed by the majority in each.
The same seems to hold true in the case of congestion pricing. In their excellent textbook on transport economics, Kenneth Small and Erik Verhoef cite surveys that find that people prefer toll revenues to be either reinvested in better road infrastructure or used to improve public transport.
This points to a paradox. The best way to get people to support such a scheme may in fact be to promise to put some tolls in place (albeit tolls that they can avoid by making different choices about how and when to travel) and then spend the revenues on giving them more transport choices.
Incidentally, I would stress the word choice in that sentence. There’s a reason why people want carbon tax revenue to be put towards renewable energy projects: it promises to give them options to avoid the tax altogether. In New Zealand, where 80% of electricity is generated from renewable sources, even a high carbon tax would have a small impact on households’ power bills. People in other countries would like to be in that same happy similar position.
The same is likely to be true for transport. If we implement congestion pricing, it might make sense to pair that with investments in public transport, walking, and cycling to allow more people to avoid the tolls. That will be more likely to lead to a win-win situation: People who value being able to drive on uncongested roads will get to pay a small price to do so, while everybody else will get to choose whether to pay the toll or travel differently.
What do you think about the politics of congestion pricing?