PROFESSOR John Kay, the eminent economist, spoke eloquently for more than an hour at Glasgow University on the economics of Scottish independence and at the end came to an unexpected but surely wise conclusion.

It's not really about economics at all. "This is much more of an emotional issue than an economic issue," he said. "The economic issues are not that big a deal. Anyone who casts their vote on economic grounds exaggerates the importance of economics."

The Edinburgh-born, LSE and Oxford academic, a former member of Alex Salmond's council of economic advisers, used his lecture to address the intriguing finding in the Scottish Social Attitudes Survey a couple of years ago that suggested Scots would back independence by a healthy majority if they believed it would make them £500 better off and reject it out of hand if they thought they would end up £500 poorer.

He was canny enough at the outset to dampen his audience's hopes of a getting a definitive answer on that.

The closest he came was to suggest that £500 either way was at the "outer limits" of what independence would mean for our pockets. In other words leaving the UK would, initially at least, not make much difference. Recalling the American revolutionaries' cry of "Give me liberty or give me death!" he noted drily: "'Give me liberty or give me £500!' does not have the same appeal."

Prof Kay's analysis goes like this. An independent Scotland would face considerable economic challenges, though they would not be insurmountable and should not be over-played.

The most pressing would be the issue of the currency. His belief that an independent Scotland would most likely have to adopt a new currency, given the restrictive economic strings that would be attached to any deal with the UK Treasury to keep sterling, was widely reported this week. However, while a Scottish currency would present "difficulties and large costs" those issues, he stressed, "should not be exaggerated".

In the longer term, creating an economic environment conducive to business success on the world stage would be the biggest challenge for an independent Scotland. Prof Kay argued that Scotland has the potential to forge a competitive advantage in a range of sectors, including food and drink, finance, tourism, life sciences and energy services (though he is deeply sceptical about a renewables-fuelled bonanza). However, we'd need to develop a more entrepreneurial climate to take full advantage.

Prof Kay is impressively dispassionate. Having concluded that independence is primarily an emotional issue, he gave no clues about where his own feelings pulled him. He did, though, seem very unimpressed with the current debate.

Pro-independence campaigners, he said, need to "get beyond vague aspirational statements of a rather ludicrous kind". Talking of the need for powers to tackle poverty was not the same as identifying specific policies that could tackle poverty, he warned. Issuing wish-lists and making promises while avoiding tough choices on tax, spending and debt placed people in "cloud cuckoo land". His verdict? "The advantage (of independence) is less that it avoids hard choices but more that it forces one to make them."

His lecture at the university's grand Bute Hall on Thursday evening was well attended. Just not by the politicians and campaigners for whom it should have been required listening. Instead they were about 500 yards away, round the corner at the student union, paying too much attention to the final stages of a mock referendum with a pitifully low turn-out of 12%.

Student leaders have been praised for arranging the mock referendum. But for me a greater debt of thanks is due to Dr Phillips O'Brien who arranged for Mr Kay to speak as part of the ongoing Glasgow Global Security Network lecture series.