Question: what do former US President Bill Clinton and Scottish entrepreneur Jim McColl have in common?

Answer: both of them waded into the Scottish independence debate yesterday, apparently on opposite sides. Come the autumn of 2014, neither man is likely to have a vote on Scotland's constitutional future. (Mr McColl is a tax exile based in Monaco.) Nevertheless, as one of Scotland's most successful entrepreneurs, he has an influential voice.

Today, in an exclusive interview with The Herald, Mr McColl calls for all political parties to lay out their stalls for how they would govern Scotland, regardless of which way the vote goes: "There are going to be elections after [the referendum] so it is up to all parties to say what would happen in an independent Scotland." In doing so, he appears to be aligning himself with the Yes Scotland campaign, whether consciously or otherwise.

By coincidence, the referendum also came up in a speech in London by the former American President, who was addressing the issue of what he called the 21st century's "identity crisis".

He asked: "Can you be Scottish and British? Can we find a way to appreciate what is separate and unique about us and still think that what we have in common with others matters more?" Unsurprisingly, Labour was quick to claim him as a supporter of the Union, though this was disputed by the SNP.

Such outside interventions should be welcomed, whatever one's personal stance on the independence question. They open up the debate, suggest new arguments to tease out and put Scotland's constitutional conundrum into a global context.

However, Mr McColl is likely to receive short shrift from the Better Together campaign. He asks the parties against independence to say what they will do if they lose but no politician is likely to be drawn into such hypothetical questions, especially when the polls suggest Scots will reject outright independence. Even the SNP will not be laying out its post-independence vision for the business community until next autumn. Why should their opponents do their work for them? Even if Scotland votes Yes, it will not be independent by 2015.

Yet Mr McColl has a point. Scotland's business community can hardly be expected to take a political view on the case for or against independence until it has what amounts to a business plan for an independent Scotland. To be persuaded to vote Yes, its members will have to be convinced an independent Scotland would perform better economically. Mr McColl is a supporter of full fiscal autonomy and having seen the idea of a second question on increased devolved powers rejected, now appears to be lining up to support full independence.

By contrast, Mr Clinton seems to be arguing that the world needs to reject what he sees as narrow identity politics and focus on common bonds, a sentiment that chimes more closely with the Better Together campaign.

It is all grist to the referendum mill, which is why we should say: all contributions gratefully received.