The answer to any question you might have right now is, basically, ‘nobody knows’. This was not a referendum with a solid plan or piece of legislation behind it: the ‘European Union Referendum Act 2015’ just said there’ll be a vote on it, nothing more. The government wanted to remain in the EU, so the campaign for the Leave vote was campaigning based on pure speculation. And, of course, presented the most optimistic possible image and downplayed any suggestion of things going wrong after a Brexit vote as ‘scaremongering’.
Here’s the situation: assuming the referendum is implemented (according to the letter of the question, if not the spirit) it looks like we can either (a) stay in something to to with Europe, but break a lot of the promises the Leave camp made and ultimately end up with a worse deal than before; or (b) completely leave and trash our economy even further.
Behind Door A there are two options, which I’ll call Norway and Switzerland.
Norway involves leaving the European Union but staying in the European Economic Area. This means we have to implement most EU laws (breaking the Leave camp promise about freeing ourselves from them), pay EU membership fees (breaking the Leave camp promise about saving the money we pay to the EU), we have to apply the four freedoms (breaking the Leave camp promise about closing the door to EU migrants), and we don’t get a seat in the European Parliament to debate the laws we’re still required to follow (breaking the Leave camp promise about increasing democracy). Since the four freedoms are maintained, this more-or-less maintains the status quo for EU migrants like me.
Switzerland is quite similar. We leave the EU and the European Economic Area, join the European Free Trade Association, and negotiate a tailor-made deal with the EU. If Switzerland is any model to go by, we still have to implement most EU laws (see above), we may have to contribute some money to the EU directly, we would still have to accept EU migrants (they would be issued visas, but without condition — see above), and we still don’t get a seat in the European Parliament to play a rôle in shaping the laws we still have to follow (see above). Existing EU migrants would need to get a visa, but it would likely be granted unconditionally.
As I write, the final result hasn’t even been announced yet and already the pound sterling has lost more of its value than in the 2008 or 1992 crashes. $350 billion has gone from the economy in a matter of hours. When we leave in two years or so, the UK loses free access to what is by far its largest trading partner. The UK is basically completely dependent on the finance industry, and so the loss of confidence in the country resulting from such an eventuality would impoverish the government. It is likely that in the coming days the UK’s credit rating will be rapidly downgraded so the government may find it harder to increase its already huge national debt to deal with this.
Some experts suggested that, due to a ‘meta-treaty’ promising the continuation of treaty rights worldwide to those already taking advantage of them, existing EU immigrants to the UK and British citizens living elsewhere in the EU would be able to stay and continue to enjoy their privileges, but that would not be extended going forward. However, whether I or anyone else from the UK can continue freely living abroad in such a case is a massive unknown at this point.