On the Principles of Political Economy and Taxation

Your Part, My Part

Maya is fast at digging. Dig, dig, dig!
Maya is fast at towers, too.

Sam is slower at digging.
Sam is slower at towers, too.
But his towers are only a little slower.

Today they want one big sandcastle.
The biggest one on the whole beach.

Can Maya do it all by herself?
She digs. Then she stops to build.
She builds. Then she stops to dig.
Maya has only two hands.
While she builds, nobody digs.

So Maya digs, fast as she can.
And Sam builds the towers, slow and careful.
Your part, my part, and the castle grows tall.

Sam is slower. Does Sam still help?
Yes! Each tower Sam builds is one less for Maya.
So Maya can keep on digging.

Say it with me: your part, my part!

The sun goes down. Look at that castle!
It is bigger than Maya could make alone.

Is Sam sad that he is slower?
Maybe a little. That is okay.
His part still counts.
Your part, my part, and the castle grows tall.

Next time you play with someone, ask:
Which part can I do?
Then do your part, and see what you build.

A note for the grown-up

For the grown-up reading aloud: This is David Ricardo’s idea of comparative advantage (1817), told with sand instead of wine and cloth. In his example Portugal can make both wine and cloth with less work than England, yet both countries end up with more when each makes the thing it is least behind at and they trade. Maya is better at both jobs here on purpose; Sam’s job is the one where he trails by least, and he still adds to the castle because Maya can’t do two things at once. The simple model leaves out that real shifts in trade can hurt particular workers badly and for years, which is a conversation for later.

I Thought Again

Leo makes a paper boat.
Leo is sure it will sink.
Paper gets wet, and wet paper sinks.
Leo tells everybody. Paper boats sink!

He puts the boat in a puddle.
He watches. He waits.
The boat floats. It floats a long time.

Leo’s cheeks feel hot.
He told everybody the boat would sink.
Now what?

He could hide the boat.
He could say nothing at all.
Leo takes a big breath.

I thought again, says Leo.
I was wrong. This boat floats.
I saw it float with my own eyes.

Say it with me: I thought again!

Is it bad to be wrong? No.
Everybody is wrong sometimes.
Saying so out loud is brave.

Leo did not change his mind because someone laughed.
He changed it because he saw the boat float.
I thought again, and now I know more.

Next time you find out you were wrong, try it.
Say, I thought again.
Then tell someone what made you change.

A note for the grown-up

For the grown-up reading aloud: In the third edition (1821) David Ricardo added a chapter, On Machinery, that reverses a view he had supported for years: he had believed labour-saving machines help every class, and on further reflection he concluded they can hurt workers, and set out his reasons in full. This story keeps only that habit, not the machinery argument, which is too heavy for bedtime. Leo changes his mind because of what he saw, not because of pressure, on purpose.