(My answer to this question on Quora.com)
The vote is clearly divided along geographical and educational lines.
In London, where people are comfortable with seeing immigrants; in Scotland & Northern Ireland, which appreciate the advantages of being in the EU; and in Oxford and Cambridge, and among university graduates and their families, who appreciated the freedom to work and live anywhere in the EU, the vote was clearly in favour of remaining.
In England and Wales outside London, Oxford, and Cambridge, and among the less educated in general, the vote was clearly to leave the EU—driven mainly by an emotional feeling that there is too much immigration into the country, and that Britain pays more than it receives from the EU, and has lost much of its sovereignty to anonymous bureaucrats in Brussels.
It will be interesting to see how things play out now. The separation will be long and messy, and while there’s a chance that the UK may ultimately emerge leaner and more self-sufficient, my gut feeling is that its withdrawal makes as much as sense as Greater Manchester withdrawing from Britain and going it alone.
What most Leave campaigners perhaps haven’t taken into account, however, is quite how lean the UK may emerge from this: because the Scots will now want to hold a new referendum to withdraw from the United Kingdom—and this time, they will likely choose to leave, because they would prefer to (re)join the European Union. In which case, the United Kingdom will suddenly find itself only England, Wales & Northern Ireland—and on its own. Thus, having lost its empire, Great Britain will also, by its own hand, have divested itself of its “Great”, and revert to being, once again, only “Britain”.
What interesting times we live in.