Why doesn't the whole wizarding world live inside a suitcase?

Question

We see on various occasions that magic can expand space. For instance, in Chapter Five of Chamber of Secrets:

"Not a word to Molly," he whispered to Harry as he opened the trunk and showed him how it had been magically expanded so that the luggage fitted easily.

And Chapter Nine of Deathly Hallows:

"Undetectable Extension Charm," said Hermione. "Tricky, but I think I managed to fit everything we need in here."

The epitome of this seems to be Newt Scamander's suitcase. In a small suitcase he has an entire miniature world of various animal habitats.

A main theme throughout the series is that the wizarding world went into hiding. Though they may live amongst Muggles they must keep magic entirely secret. We see many examples of the great lengths to which they go in order to ensure this secrecy is kept.

In light of the above facts, though, why bother with all of this? Why can't they just create their own world inside a suitcase (or any other small item). Then they would be free to practice magic in the open to their heart's content without having to worry about any Muggles. All they would have to do is hide the suitcase (or otherwise prevent Muggles from accessing it), which seems to be a lot easier than hiding every trace of magic in the regular world.

There also doesn't seem to be any need for anything in the existing world that would prevent them from leaving it. Wizards don't need any Muggle things; to the extent that they use Muggle infrastructure it seems to be mostly to hide magic from prying eyes. By relocating to a suitcase all these problems could be resolved.

Why, then, has the wizarding world not done this?

Answer 1

They’d be vulnerable to external threats.

To begin with, fitting a portion of the wizarding population into a suitcase may not be a particularly good idea. Suitcases, in essence, are portable, and can be held shut.

“HOLD ON TINA as she hides on the bridge above them, peeking down.

NEWT (O.S.)
(to Jacob)
In you hop.

We see the case sitting alone below the bridge. Tina quickly appears around the corner and hurriedly sits on the case. She closes the catches, looking shocked but determined.”
_{^{- Fantastic Beasts and Where to Find Them (The Original Screenplay)}}

This would leave any wizarding population inside the suitcase extremely vulnerable to external threats. Anyone outside of it could decide to move or destroy it without anyone inside knowing it. Newt carries his creatures in his case, but he does not leave it unattended for long. There is always someone around who is aware what is happening outside of his case.

“A particularly loud explosion in the distance. The city beneath them is starting to burn. Newt thrusts his case into Tina’s hands and takes a journal from his pocket.

NEWT
If I don’t come back, look after my creatures. Everything that you need to know is in there.”
_{^{- Fantastic Beasts and Where to Find Them (The Original Screenplay)}}

There is also the risk that something could happen in the place the suitcase is rested, like a fire or a hurricane, that could destroy the suitcase and everyone in it. Additionally, as Extension Charms do have limits, fitting the entire wizarding population would require several suitcases, not just one. As explained below, it would likely require at absolute minimum three thousand suitcases to contain the entire wizarding population. This means that wizards would have to ensure the safety of at least three thousand suitcases.

Extension Charms likely have their limits.

Though Extension Charms can greatly increase the capacity of an object, it does seem to have its limits. A writing by JKR states that theoretically, a hundred wizards could live in a toilet cubicle if they were sufficiently skilled at Extension Charms. As a hundred wizards living in a toilet cubicle is described as a theoretical case, only accomplishable by extremely skilled wizards, this would imply it is close to the bounds of what can be done with Extension Charms.

The Extension Charm (‘Capacious extremis!’) is advanced, but subject to strict control, because of its potential misuse. Theoretically, a hundred wizards could take up residence in a toilet cubicle if they were sufficiently adept at these spells; the potential for infractions of the International Statute of Secrecy are obvious. The Ministry of Magic has therefore laid down a strict rule that capacity-enhancement is not for private use, but only for the production of objects (such as school trunks and family tents), which have been individually approved for manufacture by the relevant Ministry Department.
_{^{- Extension Charms (wizardingworld.com)}}

Therefore, it would likely be beyond the capability of the Extension Charm to create a world substantial enough for the entire global population of wizards to all live in. There are at least a hundred thousand wizards in the global population, since one hundred thousand wizards usually attend the Quidditch World Cup. Therefore, the global wizarding population is likely much larger than that.

“The trouble is, about a hundred thousand wizards turn up to the World Cup, and of course we just haven’t got a magical site big enough to accommodate them all. There are places Muggles can’t penetrate, but imagine trying to pack a hundred thousand wizards into Diagon Alley or platform nine and three-quarters.”
_{^{- Harry Potter and the Goblet of Fire, Chapter 6 (The Portkey)}}

One hundred thousand wizards is just the number who are willing and able to attend the Quidditch World Cup. That doesn't account for wizards who do not like Quidditch, or were busy, or had other responsibilities, or could not afford the trip. The number in the total global population of wizards would be therefore at least somewhat higher, likely a large portion higher. After all, even though something like the soccer World Cup in the Muggle world is a very popular sporting event, only a small fraction of the total Muggle population attends it. Since it would take very skilled wizards to fit one hundred wizards in a toilet cubicle, it would likely be impossible to fit a number much greater than a hundred thousand wizards in a suitcase. It would likely not even be possible to fit the entire British Ministry of Magic in a suitcase, as there are quite a bit more than five hundred wizards in the British Ministry.

“Seats a hundred thousand,’ said Mr Weasley, spotting the awestruck look on Harry’s face. ‘Ministry task force of five hundred have been working on it all year.”
_{^{- Harry Potter and the Goblet of Fire, Chapter 8 (The Quidditch World Cup)}}

Since the British Ministry can have a task force of five hundred working on the Quidditch World Cup with enough people remaining for other functions, it must employ several more than that. Therefore, it has more than five times as many wizards as can be theoretically fit in a toilet cubicle, so just to fit the British Ministry would need more than five suitcases. Using a very conservative estimate of the global wizarding population at three hundred thousand, and considering that a suitcase (being smaller) would not hold more than a toilet cubicle, it would require three thousand suitcases to contain the entire wizarding population.

Societal functions would be difficult.

Additionally, if wizarding society was separated into groups that could fit in a suitcase, it would be difficult for the normal functions of society to continue. If each case contains one hundred wizards, from then on it would be nearly impossible for them to live as part of a larger society. The Ministry could theoretically fit into five suitcases, but then they would be cut off from the people they govern, and with no way of monitoring other suitcases, would be unable to stop crime. Wizards would have to separate into small villages containing everyone necessary for a small village to function. Each case would need, for example, its own governing body and at least one Auror. Anything that requires a large number of wizards to accomplish would become impossible. For example, the Quidditch World Cup could not continue in a society of suitcases.

“Seats a hundred thousand,’ said Mr Weasley, spotting the awestruck look on Harry’s face. ‘Ministry task force of five hundred have been working on it all year.”
_{^{- Harry Potter and the Goblet of Fire, Chapter 8 (The Quidditch World Cup)}}

This would be impossible to organize in a wizarding society split into groups in suitcases. A Ministry task force of five hundred would have nowhere to assemble, and there would be nowhere large enough to fit one hundred thousand wizards.

Some wizards are weary of hiding.

In addition, not all wizards agree that wizards should be forced into hiding from Muggles.

“GRAVES
(laughing bitterly)
A law that has us scuttling like rats in the gutter! A law that demands that we conceal our true nature! A law that directs those under its dominion to cower in fear lest we risk discovery! I ask you, Madam President—
(eyes flashing to all present)
—I ask all of you—who does this law protect? Us?
(gesturing vaguely to the No-Majs above)
Or them?
(smiling bitterly) I refuse to bow down any longer.”
_{^{- Fantastic Beasts and Where to Find Them (The Original Screenplay)}}

Those who believe that wizards should not be forced into hiding from Muggles would certainly not agree that wizards should pack themselves up into suitcases to do so.

Some wizards might not want separation.

Additionally, there are certain wizards who might prefer living among Muggles even if they have to keep their magic secret rather than live among only wizards. Even after the Statute of Secrecy was signed, some wizards still chose to live in communities alongside Muggles.

“Upon the signature of the International Statute of Secrecy in 1689, wizards went into hiding for good. It was natural, perhaps, that they formed their own small communities within a community. Many small villages and hamlets attracted several magical families, who banded together for mutual support and protection. The villages of Tinworth in Cornwall, Upper Flagley in Yorkshire and Ottery St Catchpole on the south coast of England were notable homes to knots of wizarding families who lived alongside tolerant and sometimes Confunded Muggles. Most celebrated of these half-magical dwelling places is, perhaps, Godric’s Hollow, the West Country village where the great wizard Godric Gryffindor was born, and where Bowman Wright, wizarding smith, forged the first Golden Snitch.”
_{^{- Harry Potter and the Deathly Hallows, Chapter 16 (Godric’s Hollow)}}

Getting these wizards to agree to separate entirely from the Muggles is likely to be quite difficult, and any attempt to do so is likely to face fierce opposition.

Answer 2

Putting too many eggs into one basket

Imagine if a psychopath or a dark wizard threw that suitcase with most of the wizard population inside it, into a fire, or dragged it under the sea and opened it.

Or just threatened to do it, blackmailing the wizarding world.

Answer 3

Charms don't last forever

There are frequent mentions in the series to old charms that don't work right, and the need to renew certain charms. Invisibility cloaks fade (except for Harry's), broom lose their speed, and posters become unstuck.

Obviously some charms can last for extremely long times. Hogwarts has shown no signs of deterioration, and Bill's job is to break curses placed on Egyptian pyramids. But when your entire society is dependent on a charm to function, "a really long time" isn't really good enough.

Whomever controls the suitcase controls everyone

A world in a suitcase has a single point of failure. If someone gains control over the suitcase then have power over everyone inside. That's a lot of power to rest on a single individual or organization, and a very attractive target for anyone nefarious who wants a fast track to power.

The magical community doesn't have consensus

Not everybody wants to completely segregate themselves from the muggle world. Different communities have very different standards of acceptable secrecy. And that's not even counting the magical races and creatures. How are you going to convince an angry dragon to go live in a suitcase? Are you ready to apply that technique to the hundreds or thousands of other angry dragons, who live high in mountains or other dangerous terrain?

And going away and leaving behind only those who are unconcerned with secrecy is probably a very bad way to maintain your privacy. Without anyone to pressure them or clean up their messes, the muggle world will find out about magic pretty dang quickly.

The wizarding community is arrogant

It was hard enough to convince them to go into hiding. Convince them to live in a suitcase? Now that's undignified!

The process itself would be impossible

Even if every magical person and creature decided they wanted to live in a suitcase, how would you do it? Building a working ecosystem for hundreds of thousands of people and creatures would be a huge endeavor. And then you have to migrate those people, and their homes and personal belongings into that suitcase. Who's paying for all this? It's certainly not going to be cheap.

Answer 4

Because JK Rowling is more interested in storytelling than worldbuilding.

It really is that simple. Rowling famously never read fantasy. Many of the concepts she uses are common fantasy tropes, and various authors and roleplaying systems have attempted to put them into frameworks which are internally consistent. Rowling had no idea of any of this though.

And more than that, what was important to her was telling the story. For her, the wizarding world was simply a backdrop. The essence of Rowling's writing is that the story is fast-paced, well-plotted and compelling, and that means the huge logical holes in her worldbuilding don't immediately occur to readers. Rowling herself is quite open about the ways in which the wizarding world is not consistent or logical, because it simply wasn't important to her when she wrote the books.

Other answers may well try to reconstruct some kind of in-universe explanation for these kind of inconsistencies, sure. But since Rowling herself is clear that she never intended to build a consistent world, every in-universe explanation is simply wrong. The only explanation is out-of-universe, and it is "she didn't think of it".

Answer 5

Because that isn't the solution that was reached when the wizarding community decided to go underground

Answering this in-universe, we need to look at what happened when wizards went underground. The wizarding world decided to hide itself from the Muggle world by implementing the International Statute of Secrecy, which was instituted in 1689 and put into full effect in 1692. The details of the Statute were worked out by the International Confederation of Wizards at a summit in 1692.

I think it's a reasonable assumption that the International Confederation of Wizards behaves like any governing body when determining policy and implementing new laws. Ideas are thrown around, experts are consulted, debates are held, and eventually a decision is reached. If we also assume that a) the ability to conceal their entire world in an object such as a suitcase using an Extension Charm is actually possible, and consequently b) this idea was put forward as a viable method of going underground when they were forming the Statute of Secrecy, then it would have been shot down using the very well put forward arguments from the answers already given by @Mal, @vsz, and @Arcanist Lupus, with in-universe explanations against a mass relocation into a suitcase.

Just to throw my own two cents in on it, I'd like to add two further things to the already quite solid list of arguments against putting all of wizardkind into a suitcase.

Human Rights

Why should Muggles get to walk the Earth and wizards live somewhere else? Self imprisonment is still imprisonment, no matter how big the cell, and the International Statute of Secrecy allows wizards to live without imprisonment.

Actually, wizards do need Muggles

As Ron says,

Most wizards these days are half-blood anyway. If we hadn't married Muggles we'd've died out.
_{Harry Potter and the Camber of Secrets, Chapter 7}

Answer 6

Wizards and Witches have to eat.

They cannot create food out of nothing (Gamp's Law). That means they have to farm and raise chickens and livestock, just like Muggles. So they need lots of land and fresh air and LOTS of water. Admittedly, in principle these things could be put 'in a suitcase' (although prior responses suggest otherwise, given how large farms have to be). However, there is one critical ingredient that cannot: sunlight. The sun is too vastly large and too far away to 'put in a suitcase' - also no-one in their right mind would want to kill off everyone by trying to enclose a whole star - and 'piping in' enough sunlight would require large enough openings in the 'suitcase' to make it very difficult to keep it concealed.

Answer 7

They essentially are scattered in multiple hidden worlds.

Unplotable locations, expanded interiors, external illusions, protective shields, various other protective measures, and unique combinations thereof are many ways wizarding families took to isolate themselves from the Muggles.

Why would they limit themselves to a single method of hiding?