WHEN Dr Maitland Mackie died peacefully at his Aberdeenshire home earlier this week, supporters of the United Kingdom lost a great champion and friend.

To the possibility of breaking up the UK he would certainly have said: "No Thanks."

Dr Mackie was typical of many Scots, deeply rooted in their communities and fiercely determined to contribute to their prosperity. They do not want to choose between Holyrood and Westminster, but rather have the best of both worlds, have as much influence as possible on the stage, be it domestic or international. They know influence and prosperity bring jobs and opportunities, without which there will be no social justice whoever is in power, wherever.

Now, we know that whatever the outcome of the referendum debate, and irrespective of who wins next year's General Election, the status quo is not an option. Even the Tories have capitulated, promising this week to give the Scottish Parliament powers to set its own tax and benefit rates. It is not credible to argue that the choice on September 18 is between separation or no change, and anyone who makes that case is at best disingenuous.

As the debate leading up to the referendum steps up a gear, it is difficult not to get lost or even turned off by the plethora of figures bandied about, and claims followed immediately by ever more incredible counter claims. When the highly respected Institute of Fiscal Studies says taxes would have to rise or services be cut in Scotland if the UK was broken up, it is not good enough to simply counter claim that it will be alright on the night because productivity, employment rates and population growth will grow. At best, that is a hope or aspiration. Incontrovertible evidence does not exist.

When Gordon Brown takes to the campaign trail to extol the virtues of maintaining and retaining the benefits of pooling and sharing resources across the UK, it is because he knows Scotland and Scots will be better off when the load can be shared across the UK. That is not to say Scotland cannot manage its own affairs or even survive on its own. Rather it is simply saying that the bigger the pot, the more there is to share, the more there is to invest in Scotland and its population. It is not rocket science.

Demographic change, whether in Scotland or the UK, determines much of the investment in the public sector, whether in childcare, education, health, pensions, or care for the elderly. Equally, it determines the amount of tax collected by a government.

Like every other developed nation, the UK is projected to have an ageing population, so the ratio of elderly to those of working age will rise. In Scotland, the statistics are starker and, therefore, an indisputable worry for long-term security.

According to the National Records of Scotland, Scotland's population growth is expected to be less than that of the rest of the UK. They say "the proportion of Scotland's population which is of pensionable age is projected to increase by 2.9 per cent between 2010 and 2035, compared with 1.7 per cent rise for the UK". These are dismal statistics, particularly when there is no guarantee of productivity or employment or population growth.

However productive the oil and gas and whisky industries, and however they would be divided in the event of a UK break-up, their diminishing revenues could not maintain the present level of public funding, not least because they are volatile and unpredictable. (And it is worth pointing out that although the Office of Budget Responsibility revised down oil revenues by £21 billion over the five years to 2015-16, the Scottish Government's budget rose by £2.2 billion in the same period). Any volatility in North Sea oil and gas revenues would have a much greater impact on a separate Scotland because they would make a much bigger proportion of their tax take.

The combination of diminishing oil and gas revenues and an ageing population does not bode well for a separate Scotland. Put bluntly, if we want decent public services money has to come from somewhere. And until there are definitive answers, the electorate are being asked to take a punt.