We live in a city with a traffic problem. Our only public transit is buses. However, they don’t run often and traffic makes their schedule unpredictable on top of that. So they are only used by people who can’t afford a car, and a few hardcore environmentalists. And low revenue from fares means the city isn’t able to provide good service, although some areas make up for it with a volunteer bus driver program.
If enough people took the bus, it would solve our traffic problem! Plus, the city would be able to hire more drivers — public transit would become good enough that many people wouldn’t need to own cars, saving them money.
The problem is, nobody wants to be the first to ride the bus, while it is still infrequent and unreliable. And enough people riding would solve the traffic problem for the remaining drivers, too. So, even though they all want to be rid of the traffic, everybody keeps driving and hopes that someone else will ride the bus.
Snowdrift.coop is an environmentalist organization that is interested in reducing the pollution from cars. We have an idea to get people using public transit. First, we ask the city how many people would need to switch from cars to buses to fix the traffic problem. The city says 50 000. Then, we go around asking people to sign a pledge: “If 10 000 people sign the pledge, I’ll take the bus to work every Monday. If 20 000 sign, I’ll also do it on Tuesday. …… 50 000 or more and I’ll take the bus to work every weekday.” They put down their phone number so we can notify them on each day that we’ve gathered enough signatures, and they can reply with STOP at any time to take their name off the list.