So the battle for the future of Scotland is under way. Last month’s launch of the proindependence campaign is to be followed this month by the unveiling of its pro-Union counterpart. Prepare for two years of argument and counter-argument.

Doubtless many greet this prospect with horror. Little interested in the utterances of politicians, they question why the debate will have to go on for so long. After all, they reason, all that happens in election campaigns is that politicians dodge the tough questions, and engage in yah-boo politics rather than informative debate. They see little reason the referendum campaign will be any different.

Yet, in truth, campaigns are sometimes illuminating. They can cast what turns out to be a harsh light on the appeals and claims of one side or the other. Apparently trivial mistakes made under the pressure of scrutiny – such as running into a Subway sandwich shop to escape a harangue from a left-wing activist – can serve fatally to undermine a party’s message or perceived ability to govern.

And the early days of the referendum campaign have already been illuminating, albeit not necessarily fatal for one side or the other. In particular, they have raised some interesting and perhaps unexpected questions about both the preparedness and coherence of the Yes campaign.

It has been evident for some time that perceptions of the economic consequences of independence would be central to the way that many people will eventually vote. For example, according to a MORI poll in January, no less than 36 per cent say that the economy will be most important to them personally in the debate about Scotland’s constitutional future. The next most important issue, health, trailed a long way behind on no more than 16 per cent.

Meanwhile not only did the most recent Scottish Social Attitudes survey find that as many as 65 per cent of Scots would vote in favour of independence if they thought they would be £500 a year better off, but nothing appears to matter more to whether people support independence than what they think the economic consequences of independence would be. No less than 79 per cent of those who think that Scotland’s economy would be a lot stronger under independence currently favour leaving the UK, compared with just 4 per cent of those who think it would be a lot weaker.

Moreover, the economic argument is one the pro-independence campaign still has to win.

According to Scottish Social Attitudes, while 34 per cent think the economy of an independent Scotland would be stronger, 29 per cent feel it would be weaker. Other polls paint an even less optimistic picture. According to that same MORI poll, again, while 34 per cent think economic conditions would improve, 45 per cent believe they would get worse. Meanwhile a Panelbase survey for The Sunday Times earlier this year found that while 36 per cent believe Scotland would be financially better off as an independent country, 39 per cent reckon it would be worse off. A much more positive mood about the economic consequences of independence will need to be generated if a Yes vote is to be delivered.

Yet little was heard of the economic case for independence when the Yes campaign was launched. Rather, the Yes declaration unveiled by Mr Salmond had primarily a Braveheart tone to it:‘ I believe that it is fundamentally better for us all if decisions about Scotland’s future are taken by the people who care most about Scotland, that is, by the people of Scotland,’ it begins while concluding, ‘I want a Scotland that speaks with her own voice and makes her own unique contribution to the world – a Scotland that stands alongside the other nations on these isles, as an independent nation.’ This is in essence an appeal to the hearts of Scots voters – to the distinctive sense of Scottish national identity that for most resonates more strongly than whatever sense of British identity they may also feel. However, for many Scots too that distinctive sense of identity and nationhood is not regarded as sufficient reason for leaving the UK. To win, the Yes campaign will need to combine warm feelings of identity with some hard-headed economics.

Moreover, there is one economic issue in particular which the Yes camp will need to show that it can address effectively – the implications of its wish that an independent Scotland should be part of a currency union with the rest of the UK.

Thanks to the eurozone crisis, we have learnt that monetary unions require a degree of fiscal co-ordination. Not surprisingly, therefore, questions are being asked about how much ‘fiscal freedom’ to pursue an economically stronger path an independent Scotland really would enjoy, as well as whether economic advantage can be achieved if interest rates are determined primarily by the needs of the economy in England. Those questions badly need good answers, answers that so far appear rather thin on the ground.

In truth, there was probably one key reason why the economics of independence did not play a more central role in the Yes launch – the relatively prominent role given to the Green leader, Patrick Harvie. Mr Harvie is most interested in creating a greener Scotland rather than a richer one. However, not only that but he also openly admits that he does not think we can be sure that an independent Scotland would be better off, while he questions the long-term viability of keeping sterling.

‘With friends like that…’, some nationalists must be thinking. In fact, Mr Harvie is not alone. Colin Fox of the SSP is reminding us that he does not want independence so that Scotland can attract business via lower taxes and also that, unlike Mr Salmond, he does not wish to keep the Queen.

For a long time now, we have wondered whether the three unionist parties would be able to present a coherent campaign, a doubt that has yet to be dispelled. But it seems we now have reason to wonder just how coherent the Yes campaign will be too. And incoherence rarely survives the pressure of short campaigns, let alone long ones.