Our borders are unprotected.

We need to build the wall!

If we don't--

(Adam speaking Spanish)

(Adam grunting)

(women gasping)

Building a wall would actually increase the number of illegal immigrants in America.

What? How could it possibly?

Here, I'll show you.

Just building a wall would be practically impossible.

This is where it would be.

(dog squeals)

It would have to stretch over 2,000 miles of rough terrain...

cutting through mountains,

rivers, villages

and even people's homes.

And all that destruction is monstrously expensive.

Just building the wall

would cost between $15 and $25 billion.

(woman gasps)

It would easily be one of the single most

expensive pieces of infrastructure

in American history costing as much as 20 Hoover Dams

or NASA's entire annual budget.

(man) That's one small step for man,

one giant wall for no reason.

Not to mention the astronomical cost

of staffing and maintaining the wall,

which taxpayers like you and your children

will be stuck paying forever.

I paid for the wall.

My father's father paid for the wall.

And one day you will pay for the wall.

Because this is Wall World.

Even just faking the wall for our show

was prohibitively expensive.

Looks like our CGI budget ran out.

Okay, yes, it may be expensive

but that doesn't change the fact

that once we build it, it will work.

Not like you think.

Increasing security at the border

will never stop illegal immigration.

Why not?

No one's getting passed me.

Yes, they are because it's estimated that

between 27% and 40% of all undocumented immigrants

in America came here on planes.

(plane passing)

I forgot about planes.

These immigrants didn't sneak over the border.

They came here legally through passport control,

then just overstayed their visas.

And guess what? A border wall's

not gonna stop 'em because, reminder...

You fools!

You forgot about planes!

We always forget about planes!

Even by your estimate of visa overstays,

the wall would still stop about half

of America's 11 million illegal immigrants.

No, it wouldn't.

'Cause of a little something called circular flow.

Here, I'll show you.

(dog yelps)

For decades, immigration to the U.S. was a circular flow.

People would come, work for a bit

and then after they were done, go home to their families.

Meet Douglas Massey.

Thanks, Adam.

My arms were getting pretty tired waiting for my cue.

He's a professor at Princeton

and a pioneering researcher on this topic.

When the Reagan, Bush and Clinton administrations

drastically increased border

enforcement in response

to public opinion,

they stopped that circular flow.

Not by keeping people out, but by keeping people in.

(Douglas) As it got harder and harder to go back and forth,

people crossing the border decided

they were much better off just staying in the U.S.

If I go back to Mexico now,

he won't let me back in the U.S.

I guess I'll just stay here... in Tucson.

Ironically, this increase in border enforcement

caused the number of undocumented immigrants

living in the United States to skyrocket by 248%.

It's counterintuitive, but building a wall

wouldn't stop people from coming in.

It would actually stop them from going back.

In fact, the whole idea of building a border wall

is misguided.

The Mexican economy is doing quite well right now

and population growth has slowed way down.

So, there's not much pressure to emigrate.

The number of illegal border crossings

is actually at an all-time low.

If you're a professor, then why are you in the desert?

I'm not, I'm a mirage.

(gasping) Hey!

Look, we already have what has to be the most

militarized border between any two nations at peace.

So, the real issue of immigration

isn't the people coming in.

The fact is, they're already here.

Nearly one out of every 30 people in America

is an unauthorized immigrant.

Hm, the only thing a wall stops

is a discussion of actual solutions.

(man speaking Spanish on TV)

Oh, my God, Adam, you're right.

The wall isn't the answer.

Oh, good, I'm so glad I could help.

Millions of people are already here.

We need to deport them.

Yes! Deportation is the answer.

No...

(gasping) Alfonso!