Those were the days...
I remember my friends arguing back and forth about the issue of UK entry in the immediate aftermath of the live launch of the Eurozone in '99. (Yes, I had, and still have, those kinds of friends.) None of us were economists but were pretty fastidious in reading up on the basic issues. We knew enough to know that the economics didn't point to one side or the other - after the Humean fashion of reason being the passions' slave. As much as it was an expedient for New Labour to present the issue in purely economic terms, the decision whether or not to join has clear political implications. When a (not so very far into the) future government decides on the issue, it must be frank in avowing the clear political motivation that drives its opting for the one option over the other. The basic battle line is between sovereigntists and partisans of the economy of scale.
Small is beautiful, except with Lindsey
In most areas of my life I buy heavily into the 'small is beautiful' line of argument (I can think of only two counter-examples, and Lindsey Lohan is simply irrelevant to the issue at hand). I sympathise with those, non-ideological voices raised in favour of greater government ability to tailor policy to the precise circumstances of the British economy. There's no way to avoid the argument that Eurozone strictures make this more difficult, especially if - assuming it survives another ten years - the Eurozone moves closer to fiscal as well as monetary union. However, the shock of recent events, and a sober reflection of the economic past, leads away from bespoke to off-the-peg monetary policy.
What globalism entails
It isn't just that sterling's depreciation exacerbates the UK's present woes, although membership in a wider, stronger currency would have mitigated this. My uneducated intuition is simply that the more global our challenges, the more globally-coordinated and executed our response must become. US citizens punch above their weight, relative to EU citizens, because they pool their resources. That's one very significant reason why the US possesses more tools to help itself that the EU. I sure as hell don't espouse world government as a noble, still less realistic aim, but greater assimilation of smaller units into larger, regional blocs seems to me to be the way to go.
This needn't impoverish our descendants' cultural inheritance: Scots and Welsh have managed to preserve a fierce cultural identity under centuries of rule from London. (Though the relative failure of the British union, as exampled by devolution, gives pause for thought for any more ambitious, continental union.)
I continue to believe that the issue could be resolved in something approaching a significant British majority, if not consensus, in favour of greater integration, if and only if the sting and passion of sovereigntism is removed from the national debate. This is practically impossible, given the mode and medium of national political debate, conducted as it is by polemically minded journalists and politicians. If we could ever wrestle control of this debate away from polemicists and deliver it to open-minded, empirical and scrupulous souls - a kind of Deliberative Democracy promoted by some academics - we might find a very different and more laudable national response. The nation might then decide one way or the other; but I would have infinitely greater respect for the decision, qua informed decision.