Comment: It's the economy, stupid! JOHN Curtice and Rachel Ormston argue that the key battle for nationalists and unionists is winning the argument over the financial outlook for Scotland For much of the past year, the referendum debate has been about process not substance. The perennial questions have been, "when should the ballot be held, who should be able to vote and should there be one question or two?" By all accounts, we are now entering the end game on these issues - leaving battle to be joined at last on the central issue: "What kind of constitutional future does Scotland want?" But if that debate is to be effective, it will need to address the concerns of voters, rather than the preoccupations of politicians. This week, research based on the Scottish and British Social Attitudes surveys gives us vital clues as to what those concerns might be - and what are the issues that might determine which path Scotland will choose to follow. In the eyes of some nationalists, the argument for independence is simple and straightforward. Scotland is a nation whose people have a distinct sense national identity. All nations have a right to run their own affairs and, so, Scotland should be an independent state. Beyond that there is nothing more that needs to be said. Many Scots do indeed have a distinct sense of national identity. Hardly anyone regards themselves as British rather than Scottish, while nearly one in three not only claim to be Scottish but also go on to deny being British at all. That would seem to be fertile soil in which an independence campaign could reasonably hope to grow and prosper. However, for many people being Scottish is not sufficient reason for backing independence. Even among those who say they are "Scottish, not British," only just over half want Scotland to become "independent, separate from the UK." Even when the idea of independence is expressed in much softer terms, such as "the Scottish Parliament should make all the decisions for Scotland," still no more than two-thirds (65 per cent) of this "exclusively Scottish" group are in favour. While it is undoubtedly the case that relatively few people who lack a strong sense of Scottish identity back independence, many who do have such feelings do not find them sufficiently compelling to want to leave the Union. In practice, of course, the debate about independence is not just about whether Scotland "ought" to be independent, but also about its anticipated practical consequences. Would an independent Scotland be a more or less influential player on the world stage? Would an independent Scotland be a fairer or less fair place to live? And, above all, would an independent Scotland be economically better or worse off? Perhaps it is these issues that matter more in determining what view voters will take. In many respects, Scots take quite an optimistic view about what would happen if their country did leave the UK. Two-thirds agree that people would have more pride in their country, while hardly anyone takes the opposite view. Equally, about half reckon Scotland would have a stronger voice in the world, while only one in five believes its voice would become weaker. In some respects at least, it would appear the argument for independence has already been won. But when it comes to the possible economic consequences of independence, Scots prove to be much more equivocal. Only about a third believe that the economy would be better or the standard of living higher. Almost as many think the economy would be worse. The economic case for independence may not be widely regarded with the derision that some unionists have tried to heap upon it, but evidently it is still widely regarded with scepticism. That scepticism matters. Whether or not people think that independence would result in a stronger or weaker economy is strongly linked to whether they support or oppose independence. More than three-quarters of those who think that Scotland's economy would be "a lot better" under independence back the idea. In contrast, few who reckon the economic consequences would be disadvantageous do so. No other expectation about what would happen should Scotland become independent is more closely linked to whether or not people back the idea. Indeed, the link between attitudes towards the economic consequences of independence and whether or not people favour leaving the UK appears to be markedly stronger than that between national identity and people's constitutional preference. While those who say they are "Scottish, not British" are about five times more likely than those who are "British, not Scottish" to support independence, those who think the economy of an independent Scotland would be "a lot better" are nearly 20 times more likely to back the idea than are those who adopt a markedly pessimistic view. Not least of the reasons why the economic debate matters to voters is that unless they are convinced of the financial benefits of independence, they are inclined to be worried about the prospect of independence. No less than 88 per cent of those who think the economy of an independent Scotland would be worse express such feelings. Indeed, overall nearly half of all Scots (46 per cent) say they are worried about independence. Many a voter will be in need of considerable reassurance before they will be willing to put an "X" in the Yes box. So, the outcome of the referendum could well turn on who voters eventually judge to have won the debate about the economic consequences of independence. It is certainly difficult to see how the SNP can hope to press its case successfully unless it can create a positive climate of opinion about the country's economic future. Just persuading people that independence would not be economically disadvantageous would not be enough; most of those who think independence would not make much difference either way economically are at present inclined not to take what they perhaps regard as the unnecessary risk of leaving the Union. Indeed, even among those who feel the economy would be no more than "a little better," independence fails to secure majority support. Many a voter will struggle with some of the arcane details of the economic debate. Such questions as "would the public finances of an independent Scotland be healthier than those of the UK?," or "how could an independent Scotland both keep pound and have the freedom to pursue its own fiscal policy?" do not immediately stir the heart of anyone who is not an economist. But Scotland's constitutional future probably depends on who can come up with the best answers that the rest of us can readily understand. John Curtice is research consultant to ScotCen Social Research and Professor of Politics at Strathclyde University. Rachel Ormston is a senior research director at ScotCen Social Research. Further details of their research can be found in the latest British Social Attitudes report, freely downloadable at www.bsa-29.natcen.ac.uk/