For all its virtues, though,Capital in the Twenty-First Centuryis still a doorstop-size book.

How did you approach translating it into a documentary?

It’s an academic book.

CAPITAL IN THE TWENTY-FIRST CENTURY

Credit: Everett Collection

He traveled through time, and saw history not so much repeating as rhyming.

It’s a great barometer of the feeling on the ground at the time.

I knew I wanted to use pop culture, so that was a big thing straight away.

That’s where it started.

I wrote a treatment, given to Thomas, and he liked it.

The film begins with the definition of capital and then goes through the historical evolution of the concept.

How did you wrap your head around the challenge of explaining capitalism in a cinematic way?

I wanted to look at history through the lens of capital: What was capital doing?

How did this impact capital?

That’s the way I thought it would hopefully be a character in the film.

You know what’s crazy?

We actually referred to capital as “the virus” in one of the treatments.

I also thought of it sometimes as a wild animal that could be tamed.

One of the disciplines I brought was that the culture has to be from the period.

That was a challenge because there was no archival footage before World War I.

It’s a black-and-white film from the 1900s, but its words were written in that period.

Thomas really loves pop culture as well, which was a surprise when I met him.

He said his favorite film at the time was the one with the train,Snowpiercer!

I was like “Okay, he loves sci-fi!”

So he was up for all that.

I’m delighted to learn that Thomas Piketty loves the films ofBong Joon Ho.

Oh, he does!

I learned he’s a Piketty fan too!

They’re both fans of each other’s work, which was nice to hear.

It’s kind of remarkable when you think about it like that.

What can this film tell us about this moment?

It’s a shocking depiction of inequality at its worst.

Depending on which way this goes, it’s likely to exacerbate it.

When we were making the film, it’s the world we were imagining could happen.

But now the film’s coming out as it’s happening, and that’s not good.

It makes the film feel more urgent, which is perhaps good in terms of maybe effecting some change.

So I guess the positive note is that this could be a catalyst for change.

One thing is that change starts with people talking about ideas.

In a sense that’s simple, but it’s so powerful.

It’s taken a long time, but now most people want some action.

It’s distorting things.

Also the dangers of inheritance.

But look how quickly the wealth tax has entered the debate in America.