The Ending I Forgot for John Henry & an Example of a Jevons Paradox

I recently listened to the story of John Henry again, and it hit me differently this time.

I highly recommend the version narrated by Denzel Washington, with music by B.B. King.

There is something powerful about the pride at the center of the John Henry story.

The pride of building something with your own hands.

The feeling of looking back at the end of the day and seeing what you made. What you moved. What exists now because you were there.

John Henry represented that pride.

He was the man who could drive more rail, build faster, and even beat the machines brought in to replace the work he did by hand.

And he won!

John Henry beat the machine.

The ending I forgot

But there is one part of the story I don’t remember hearing much as a kid.

John Henry died with his hammer in his hand.

Maybe that part didn’t make it into many children’s versions of the story. But it changes the lesson.

John Henry proved that a person could beat the machine.

It just cost him everything.

That kind of work ethic isn’t sustainable. Most of us know that.

More railroad, not less

After John Henry, the machines kept spreading.

Rail drivers became rail operators. Work that once required several people on one rail line could now support work across several lines. Railroads could be built faster and at lower cost.

That mattered far beyond the people laying track.

More railroad meant more transportation routes. More routes opened more places to trade and do business. Cheaper transportation made it practical to move more goods over greater distances.

The train itself was obviously important to commerce. But so was the ability to build the railroad quickly enough and cheaply enough to make a large rail network practical.

Once building rail became cheaper, rail could also solve smaller transportation problems. A company could use it to move material only a few miles between its own plants when that became faster and cheaper than the previous option.

When the cost of doing something falls, people usually don’t stop doing it.

They find more reasons to do it.

The same pattern with AI

We have seen that pattern in industry and technology, and we’re seeing it with AI now.

TypeSafe AI’s new model, Jev, made a lot of news because of the value it offers for the cost.

Its job is simple. It can decide the next action or categorize a topic without producing a long explanation or visible thought process for the user. It gets from question to answer using as few tokens as possible.

A large amount of AI work looks exactly like that.

If Jev can make those tasks significantly cheaper, then more people can afford to use AI for them. Tasks that were previously too expensive or too small to justify suddenly start to make sense.

And when something becomes cheaper to use, people often use more of it.

That idea is known as the Jevons paradox, which is what Jev was named after. The economist William Stanley Jevons described it in 1865, in The Coal Question: as steam engines got more efficient with coal, Britain did not use less coal. It used more.

The railroad story gives us an easy way to see it.

Machines made laying rail faster and cheaper. That didn’t make railroads irrelevant. It made more railroad projects practical.

AI can work the same way.

If the cost of completing a task falls far enough, we don’t simply save money on the tasks we already do. We start doing tasks that previously weren’t worth doing at all.

More ideas become practical.

More problems become affordable to solve.

More people get access to tools that used to cost too much.

So maybe the most interesting question in the John Henry story isn’t whether a person can beat the machine.

John Henry already answered that.

The better question is: why are we so determined to fight a tool that can help us build more?