Mervyn King, former governor of the Bank of England, has written the best article I've read on Britain's exit from the European Union. In an essay for the New York Review of Books he makes many excellent points, but one is of surpassing importance. It's an obvious point, or ought to be, that nonetheless has been almost entirely ignored by other respectable commentators: Whether Britain should stay in the EU depends on where the EU is heading.
The EU is plainly in deep trouble with or without the United Kingdom, and its condition as a political project is anything but stable. Judging whether Britain is better off as a member therefore requires a judgment not only about what Britain has gained or lost from membership up to now but also an assessment of the future character of the whole EU enterprise. Britain's "remain" campaign, expressing the collective opinion of every expert on the subject, has had almost nothing to say about this.
As King points out, the EU is structurally unsound. (Joseph Stiglitz in the Financial Times makes the same point.) It has pressed political union both too far and not far enough. That is, it has created half a political union — with a single currency but without a collective fiscal policy or the political apparatus that would be necessary to legitimize it.