The first time I took an online taxi cab – I was nervous. Here I was on a street corner, using an iphone app (Uber or Lyft) to call a random driver. Who was this mysterious person? If anyone with a cellphone and a car can turn their vehicle into a cab . . . what is to stop him from driving up next to a cliff and pushing me out the door?

The cab pulled up, and the driver immediately got out of the car, greeted me with a big smile, and opened the passenger door. “How are you?” he said, “Long day at work?”

It was a long day. It was a terrible day. I didn’t feel like being nice to anyone. In fact, I felt very much like being rude. My first day on the job, I had two big zits on my face, and the contacts in my eyes were bothering me so much that I could barely even see. I had to keep one eye closed all day . . . it was torture! I was not in the mood to be friendly at all.

But then I remembered something. Uber uses a 5 star rating system. At the end of the ride, the customer rates the driver, and the driver rates the customer.

So I thought – “I want those stars!”

When I got in the car, my instinct was to slump over and completely ignore the driver. But because I didn’t want a horrible rating, I said, “Hi, I’m really sorry, but I’ve had a terrible day, and my contacts are hurting my eyes, so if it’s alright with you, I’d just like sit here in silence with my eye closed. I hope you don’t think I’m being impolite . . .”

“Oh no, I’m so sorry to hear that,” said the driver, “It must be terrible! I’ll keep quiet so you can rest.”

“Thank you,” I said, hoping to get another star.

While the driver zipped to my destination, I felt this market force continuing to evoke me to be even more courteous to him. I said, “So have you had a busy day?”

“Yes,” he said, “But don’t worry about me. Just feel free to rest my friend. Soon you’ll be home.”

It was an amazing experience. It was as if the invisible hand of the market was somehow evoking the most polite cab ride possible. It was the first time I’d felt the market force for morality so clearly. As if we were both pointing a gun at each other to be nice.

At the end of the cab ride, I asked the driver if the cab rides were nicer with Uber, compared to the yellow city cab. He said, “Yes! The customers are even friendlier!”

We wished each other farewell, and the driver pulled away. I pulled out my iphone and gave the driver 5 stars. Currently, the Uber system does not allow customers to see their own rating (Lyft also keeps it a secret, but will tell you if you ask them). The rating is used only in cases of a dispute. But I was curious about my stars. Did the driver give me 4 stars for being stressed? Or 5 stars for being extra polite? I wanted to know.

Many people say that in a pure free market system, there would be no morality. The world would turn into survival of the fittest, and life would be a violent battle. Perhaps the streets would be filled with drivers racing and getting into car accidents, and shouting matches.

Perhaps. But the Uber experience demonstrates that there is a market for morality in the world. And even though the rest of society might not use an Uber-like rating system, reputation still matters. If I eat at a restaurant without paying, I might get away with it. But if I get caught, the restaurant will make sure they never serve me again. Similarly, if the restaurant serves me poorly, then I’ll give them a poor rating. The market for morality exists throughout society without anyone giving it a second thought. The invisible hand persuades all of us to be kinder, and more helpful people. And after my short ride in the Uber car, I somehow felt like a nicer person. Perhaps voluntary exchange does encourage everyone to be friendlier and happier.