Previous: What Scarcity Is and Isn't

Space is scarce. Strength is scarce. Money is scarce.

Time is scarce. Time is really, really scarce.

Why?

Maybe because we're running out of it. Each of us has only so much time on this earth, and the Earth itself has only so much time before the sun eats it, and the sun itself has only so much time before it dies, leaving our tiny part of the galaxy cold and desolate, and the galaxy has only so much time before the universe ends.

There is only so much time. Surely that's why time is scarce.

Let's imagine a robot programmed to eat oranges from the orange tree that grows in the garden where the robot eats the oranges from the orange tree that....

And it knows that time is running out.

Soon I will end, thinks the robot as its metallic arm extends forth to pluck an orange off the branch.

Soon all this will end, it thinks as it carefully peels the orange with its delicate, precise fingers.

Soon all will be naught, it thinks as its metal teeth crush the thin, almost plastic-like membrane that so utterly fails to protect the sweet fruit. Sticky juice gushes down the robot's chin, the sun explodes, and the universe ends.

Was the robot's time...scarce?

Its time was certainly limited! No doubt about that. But was it scarce?

The robot was programmed to eat the fruit of the orange tree that grew in the garden...and that was what it did. Its body, its energy, its attention, focus, and time were all devoted to that sole task by programmer fiat, and it could not choose otherwise.

The robot's time, then, although limited, and though the robot may have enjoyed its time and wanted more of it, nevertheless had no alternative uses.

No matter how much or how little time the robot had, its "choice" would have been exactly the same. And a choice from a choice set consisting of one element is no choice at all.

What can the sciences say about this situation? A physicist could describe at length the mechanics of how the robot works and why it will eventually stop working, along with the whole universe. A biologist could explain the orange tree: how it grows and replenishes itself year after year, and why it will eventually stop doing so. A robopsychologist could study the robot's brain, the pleasure it gains from the orange fruit and the fear it experiences at the knowledge of its inevitable demise.

But an economist? I haven't the faintest idea what an economist could say about this situation. And should that surprise us? After all, this robot's rapidly dwindling time is not scarce....

So why is time scarce, for people if not for robots? Simply put, it's because our time has alternative uses, and theirs does not because we can make choices. Time we spend at the movies is time we can't spend at home reading a book. Time spent studying in a library is time not spent playing outside. Time spent making love to one person is usually not time spent making love to another person.

Because there are more things we would like to do in the time available to us than we can choose do in the time available to us, the resource becomes scarce, and we have to choose how to allocate it.

And economists have a lot to say about that!

Next: the three kinds of cost....