The Economy Would Be More Fair With Mario Kart 'Rubber-Banding,' Experts Say

We hate the blue shells, but they create a critical solvent that makes 'Mario Kart' an equitable game for all. Environmental movements must learn from the blue shell.
Wario leveling the field
Image: Nintendo screengrab

No one likes it when the blue shell, which attacks the person in first, comes for them in Mario Kart. But the presence of the power-up helps keep the game fun and fair for everyone playing. According to environmental researcher Andrew Reid Bell, Mario Kart and its blue shell have a lot to teach us about environmental stewardship.

It’s the subject of his new research paper, “From Mario Kart to pro-poor environmental governance,’ published in the February issue of Nature Sustainbility. It is also reminiscent of a legendary 2014 blog post by video game designer, professor, and games writer Ian Bogost.


Bell’s argument is that the development of agriculture was once a path to prosperity for the world’s poor. That’s no longer true and the alleviation of poverty will require new mechanisms for a new world. “A model for part of that path may already be laid out, through a pro-equity, inclusive system that is known across the globe and predates the modern pro-poor literature: Nintendo’s Mario Kart,” Bell wrote in his paper.

The center of the metaphor is the rubber-band effect. Mario Kart regulates its game with powerups. As human players drift to the back of the pack, they’re given better power-ups to help them get back into the race; players who are near the head of the pack are often given single bananas or green shells, which are not nearly as useful as stars, mushrooms, blue shells, and lightning. The most drastic power-up is the blue shell, which works differently in every game but is typically given to players at the back of the pack and targets players at the head of the pack. Some rubber-band systems artificially make cars at the front slower and make cars at the back of the pack faster without the use of power ups.

Bell argued that Mario Kart’s rubber-band system is a powerful metaphor for the kind of targeted relief governments need to use to create a more equitable world. “In any room of professionals or decision-makers, anywhere in the world, someone or their kid plays Mario Kart,” he told Motherboard in an email. “That makes it potentially powerful, because the same people who might launch the next social or environmental program are people who can relate to Mario Kart.”


He said these kinds of metaphors are important for policy makers. “It shows us this important social feedback mechanism that’s rare in practice—a balancing feedback that pulls harder at people in the back as the distance from the front grows,” he said. “So many of the things we do in practice—think, reinvesting profits in a business, paying for schools with local property taxes—are reinforcing loops that tend to increase gaps between groups, and it’s really helpful to have this shared, relatable gaming experience to build on.”

Bell admitted the metaphor has limits. “The systems view of rubber-banding in games versus reality highlights where Mario Kart stops and real pro-poor interventions must continue. The designers of Mario Kart don’t care who wins the race or when—only that the race is close enough to stay fun,” he said in his paper. “Rubber-banding in Mario Kart is a simple pair of balancing feedback loops that pull lagging racers forward, indifferent to the pace of the lead racer. In contrast, rubber-banding in both the asymmetric and symmetric resource contexts illustrated here is driven partly by a reinforcing, positive feedback for those in the lead, whose self-improvement is part of the driver for gains at the back.”

According to Bogost, who wrote "The Blue Shell and Its Discontents," Bell misunderstands how Mario Kart’s rubber-band system works. “First, the AI tries to slow down computer players ahead and speed up computer players behind them,” Bogost told Motherboard in an email. “That is to say, the effect is not (just) applied to the whole system, but to the system as it relates to the human players specifically. That is, my read of Mario Kart is that rubber banding is used to help individual human players close their gap with the next one or few karts, not to attempt to equalize the field more broadly.”

Not all racers in Mario Kart are created equally and the game specifically tailors the experience to the human participants, not all racers broadly. There’s also the problem of power-up deflation and the fact that the blue shell which equalizes the field feels like a visible punishment for winning. “That’s not a ‘golden mushroom’ at all, in the metaphor the paper uses for a loan or a subsidy, but something more like a tax or a restriction on the leading groups,” Bogost said. “But even then, the Blue Shell usually isn’t redistributing opportunity anyway, except among those already close to the front of the pack.”

Like any broad metaphor, the Mario Kart path to economic prosperity breaks down if inspected too closely. “By and large, all the Blue Shell does is to temporarily inconvenience the leaders such that another close competitor who might have taken the lead anyway can have a chance to do so,” Bogost said. “When combined with the localized AI rubber-banding that makes karts behind you faster than they would be otherwise, it seems like the system on the whole is more concerned with maintaining the general position of the best players, while simulating to the worst that they have a shot at victory—which they probably don’t.”

Bell is aware of the shortcomings of his metaphor, but believes in the power of Mario Kart to start conversations and help people immediately understand the rubber-band effect. “What I’ve been happy about though is that starting with Mario Kart and then talking through what you have to add in order to make it real, still helps you identify these essential elements of what will make interventions truly pro-poor,” he said. “They don’t happen on their own—you really have to be deliberate about building them in.”