It is actually super simple, okay? It's one of the most basic questions in economics, and once you get it, you'll see it everywhere. Trust me.
The Big Problem Nobody Gets
Here's the deal: Water keeps you alive. Without it, you're dead in three days. Done. Finished. Diamonds? You can't eat them. You can't drink them. They just sit there looking pretty. So why does a bottle of water cost you what, a dollar? While a tiny diamond costs thousands?
This used to drive economists absolutely crazy. They called it the "paradox of value." Fancy name for something that made zero sense to them.
The Old Answer Was Completely Wrong
For a really long time, people thought stuff was valuable because of how hard it was to make. Like, "Oh, this took 100 hours to build, so it's worth more than something that took 10 hours." Makes sense, right?
Wrong.
Here's why that's stupid: Jonas Salk spent years developing the polio vaccine. Years! By this logic, it should cost a fortune. But he gave it away for free. Why? Because value isn't about how long something takes to make. It's about what people want and how much they want it.
Adam Smith himself couldn't figure this out. The father of economics, the big genius, and he was stumped by diamonds and water. That's how tricky this was.
Then This German Guy Figured It Out
Hermann Heinrich Gossen came along in the 1800s and basically said: "You're all looking at this wrong."
He created what we now call Gossen's Law, which is really simple:
>" The price of something is determined by what the last unit is worth to people. Not the first unit. Not the average unit. The last one. "
Think about it like pizza. The first slice when you're starving? Amazing. You'd pay good money for that. The second slice? Still great. Third? Pretty good. By the eighth slice, you're like, "Get this away from me." That eighth slice is worth basically nothing to you, even though it's the exact same pizza as slice number one.
Water Is Everywhere, So Nobody Cares About the Last Drop
Water is abundant. It's everywhere. You use it for everything:
- Drinking (super important)
- Showering (pretty important)
- Flushing the toilet (okay, fine)
- Washing your car (who cares, really)
- Hosing down your driveway (why are you even doing this?)
The price you pay for water reflects all these uses, not just the life-saving drinking water. It's priced based on what the last gallon is worth, and that last gallon is probably being used to water your lawn or something equally useless.
As economist Thomas Sowell put it, people are "willing to repay the costs incurred in the production of what they want." But here's the thing: they're only willing to pay based on how much they want that next unit, not how much they needed the first one.
Diamonds Are Rare, So Each One Matters
Now diamonds. There aren't that many of them (well, relatively speaking). Most people don't have one. So when you get a diamond, it's special. The marginal satisfaction, the extra happiness you get from one more diamond, is huge. Even Elizabeth Taylor, who had a ridiculous collection of jewelry, still wanted more diamonds. That last diamond she bought? Still super valuable to her.
If diamonds were as common as rocks, they'd be worthless. But they're not, so they're not.
The Trick Nobody Uses (But Could)
Here's something wild: If water companies knew you were dying of thirst in the desert, they could charge you thousands for that first bottle. You'd pay it! You'd have to! Then they could sell you the second bottle for less, the third for even less, and so on.
But they don't do this because they can't. They don't know who's dying of thirst and who's just washing their car. The cost of figuring that out would be insane. So they charge everyone the same price based on the average use, which is pretty boring stuff.
Why This Matters (And Why Nobody Teaches It)
John Maynard Keynes once said, "The difficulty lies, not in the new ideas, but in escaping from the old ones, which ramify, for those brought up as most of us have been, into every corner of our minds."
Translation: Old ideas are sticky. Really sticky.
Bertrand Russell took it further: "The resistance to a new idea increases as the square of its importance."
Think about it. Geologists fought plate tectonics for decades. Doctors rejected germ theory until the late 1800s, even though it explained literally everything about disease. Why? Because changing your mind is hard, especially when you've built your whole career on the old way of thinking.
The subjective theory of value, the idea that value comes from what people want and not from how hard something was to make, still isn't taught in most business schools. It's crazy! But when you explain it to regular people, they get it immediately. Because it's how they actually behave. It's how everyone behaves.
The Bottom Line
Value isn't about what something costs to make. It's not about how useful it is overall. It's about how much you want the next one.
Water? You've got plenty, so the next gallon is worth almost nothing.
Diamonds? You've got none (probably), so the next one is worth a fortune.
That's it. That's the whole thing. And once you see it, you can't unsee it. You'll notice it everywhere: why concert tickets cost more for good seats, why the first beer tastes better than the fifth, why people pay more for rare Pokémon cards than common ones.
It's not complicated. It's just that nobody wants to admit they were wrong for 200 years.