It used to be hard to get a taxi.

No, seriously.  I’ve lived in Boston for over 15 years now, and I have memories of calling cabs who never came, waiting on corners for the sight of one to flag down, calling the dispatcher back to ask where they are, and generally hating the whole process.  It always seemed like no matter which taxi number you called, you got the same harried dispatcher who was not thrilled that you were calling to request a cab.

When Uber came along, it was relieving.  I could use my app to request a taxi, I could at least know for sure that one was assigned to me, and see its progress towards me.  It might still take some time to reach me, but I felt like I had more control.

Now with Uber-X I can request someone to arrive at my door within minutes, even on off-hours. (Like today, at 4:30am.)  There are usually plenty of drivers on the road.  My entire routine of getting to the airport has changed, because I can rely on a car arriving when I want it, rather than factoring in time for wrangling a cab.

What’s most interesting to me (and this is where that PhD my mother wanted me to get in math would come in handy) is that in a pretty random system, this can be true.  That is, some number of people got up this morning, decided, “I’ll drive for Uber today” and enough of them ended up in my neighborhood at the right time so that when I needed a car, I could get one quickly.

Mass transit isn’t that efficient.  The taxi system isn’t that efficient.

I know that Uber does some amount of controlling the number of cars on the road with their surge pricing.  But Uber doesn’t assign territories or control whether cars are moving around or sitting still, or where they are.  Plus, there was no surge this morning.

It makes me wonder what other kinds of systems can be efficient in a purely random way.  I’m reading Who Gets What and Why about market design, and it’s got me thinking a lot about this.  But the experience I had this morning is more than just market design, I think.  It’s also about “randomness in a densely populated system”?

Stay tuned.