SCOTLAND'S politicians could do worse than stop obsessing about our constitutional future for long enough to join in this week's celebrations of the remarkable changes made possible when people take charge of what's around them.

These changes are taking place in the Highlands and Islands, where thriving economies and rising populations are increasingly to be found in places that seemed destined never to recover from the damage inflicted by landlords of the sort who ordered the Highland Clearances.

Nowhere needed such a boost more than Gigha, which, in recent history, has been bought, sold and bought again by a succession of mostly absentee proprietors. During the last two decades of the 20th century, the island changed hands three times. Its lairds lacked the time or inclination to invest in the place, leaving local people with few opportunities and still less in the way of adequate housing. Many left and by 2001 Gigha's population, which once topped 400, had dipped below 100.

Since the formation of the Isle of Gigha Heritage Trust, a remarkable change has been brought about. When the locally-elected organisation took control in 2002, local housing was in a poor state. Of the 40 or so homes available for rent from Gigha's landlords, three-quarters were below the officially tolerable standard, and all bar one of the remainder were "in serious disrepair". A Gigha resident, it was calculated, was 80 times more likely to be living in a substandard home than people in Scotland as a whole.

Today, more than half those 40 homes have been refurbished by the Isle of Gigha Heritage Trust. Others are scheduled for renovation. Eighteen new homes for rent have been built. And on an island where previous proprietors refused to sell house sites, a dozen or so privately owned homes have been constructed on land sold by the community.

Developments like this – plus the launch of private businesses that couldn't previously get off the ground for lack of premises – have brought about a reversal of the population loss. In 10 years, population has leaped by 60% and the school roll has more than tripled.

On a springlike day of the sort that comes early to Gigha, the most southerly of the Hebrides, I talk to John Martin, an island joiner, about what the islanders have accomplished. "If someone had said 10 years ago that we'd have achieved by now as much as we have achieved," he tells me, "I'd have said they were dreaming. What has been realised here is far beyond my expectation."

In Knoydart, community ownership has brought even more population growth and, as in Gigha, there are young folk around for the first time in ages. Two of them are sisters Isla and Rhona Miller, who grew up on the peninsula. In the old days, they would have quit on leaving school, never to return. Instead, after

completing their education in Glasgow, the Miller sisters came home to start their own thriving business, Knoydart Pottery And Tearoom, in premises made available by local ownership trust the Knoydart Foundation. "This is a great place to live," says Isla. "There's always something going on. Yes, we have to make our own entertainment. But with more and more people around, we're getting pretty good at that."

This is music to the ears of David Cameron, the Harris businessman who helped bring the North Harris estate into community ownership in 2002 and who now chairs Community Land Scotland (CLS), the community ownership movement's increasingly effective lobby group. "It's every ownership trust's most basic task to improve living conditions in the communities we're here to serve," says Cameron, who will be in Mull this week for CLS's annual conference. "The people we represent need more and better housing. They need more and better jobs. We have to be seen to be providing these."

That is happening. The 20 or so local trusts that got together to set up CLS have shown that depopulation can be reversed, businesses created and homes built in localities where these things once seemed impossible. They have demonstrated that wind power and other resources can be harnessed for local purposes. They have proved that previously loss-making sporting estates can be run at a profit. They have shown that people living in the Highlands and Islands are just as capable as any outside body of looking after the area's outstanding natural environment.

So what's not to like about community ownership? The public money it swallows up, say critics. But they couldn't be more wrong. As CLS insists, and as the record shows, community ownership is a highly cost-effective means of delivering lots of the things Scottish and British governments keep saying they want to bring about.

The area now in community ownership is larger than North Ayrshire, West Dunbartonshire and East Lothian combined. But getting this big tract of territory into local hands has cost Highlands and Islands Enterprise (HIE) and the National Lottery (the main external funding sources) just £30 million between them. That's no tiny sum. But it scarcely compares with the quantities of public money spent elsewhere. It equals the cost of just one 600-yard stretch of the tramway intended to link Edinburgh's city centre with its airport. It's equivalent to what UK farmers and landowners – groups inclined to complain about the cost of land reform – get by way of subsidy from the public purse every three or four days.

All Scotland's political parties have a stake in Scotland's community ownership success story, which began when the Scottish Crofters Union (SCU) suggested that government-owned crofting estates be given to the people living on them. In 1989, Russell Sanderson, a Scottish Office minister in Margaret Thatcher's Conservative Government, took up the suggestion, piloting the idea on Skye and Raasay estates owned by the then Department of Agriculture.

In the event, crofters on those estates opted to remain the department's tenants. But work done there by Stornoway lawyer Simon Fraser, who took the lead in devising the legal mechanisms that would have been needed had the Sanderson initiative succeeded, was not wasted. In 1992 crofters in Assynt, on Sutherland's west coast, asked Fraser to help them mount what became the first community buy-out of a private estate – one located in an area where 50 communities were emptied completely during the Highland Clearances. Some questioned whether crofters could really do a better job of managing Assynt than the wealthy landowners of old. "Well," said Allan MacRae, chairman of the newly formed Assynt Crofters' Trust: "I can't see how we can do any worse."

Among visitors to Assynt at that time was the Tory Scottish Secretary Michael Forsyth. Having first made clear, a little superfluously, that he was "no Bolshevik", Forsyth urged other crofting communities to follow Assynt's lead. He told the (previously hostile) Forestry Commission to get serious about community ownership, and in 1997 he pushed through Westminster the first Scottish land reform legislation of modern times – in the shape of a Transfer of Crofting Estates Act.

That same year, 1997, saw islanders on Eigg raise the £1.5 million (barely 1% of it from the public purse) they needed to buy the island from its laird, a German artist called Maruma. Fifteen years on, Eigg, like Gigha, has been transformed by islander-managed initiatives such as the construction of Eigg's globally unique electricity grid.

When Eigg residents first advocated community ownership, they were dismissed by the island's pre-Maruma landlord, English businessman Keith Schellenberg, as "barmy revolutionaries". Today these same islanders, along with people who have moved in since community ownership made this feasible, have attracted numerous national and international awards for their electricity grid and other accomplishments.

Back in June 1997, on the day Eigg folk took possession of their island, Brian Wilson, a Labour minister following Tony Blair's recent election victory, announced the formation of HIE's Community Land Unit (which has since helped other communities keen to follow Eigg's example). That same year, Scottish Secretary Donald Dewar set up a Land Reform Policy Group. Its work paved the way for the Scottish Parliament's Land Reform Act of 2003 – a Labour-LibDem measure. Though opposed by Tories, now cooling on the community ownership concept, the act was backed by the SNP, who argued that it didn't go far enough in community ownership terms, but was a step in the right direction.

Despite Conservative opposition to the Land Reform Act, Tory, Labour, Liberal Democrat and SNP politicians have all had a hand in community ownership's success. Which is why it might be appropriate if these four parties were to be represented on Gigha this Thursday. Best of all would be a visit to Gigha, Eigg, South Uist or some other community-owned property by First Minister Alex Salmond. After all, the transformation brought about by community ownership has been hailed by some as indicative of what Scotland might achieve through independence. For English businessman Ian Scarr-Hall, for example, involvement in the community purchase of North Harris persuaded him that a self-governing Scotland might make sense. "Being a partner with the [North Harris] community enabled me to witness the immeasurable energy that is released when a community takes ownership of its destiny," he explained. "There was something indescribably empowering about standing with a group of people and charting a new, brighter future. That is the same sentiment that has led me to believe in independence and freedom for Scotland."

A visit to a community-owned estate would also help publicise community ownership successes and give Salmond a chance to learn what policy initiatives are needed if the sector is to grow further.

Despite the SNP's dismissal of the Land Reform Act of 2003 as insufficiently radical, the party has been reluctant in office to advance the reform cause. A welcome relaxation of that stance came last month with the announcement of a £6m investment in a new Scottish Land Fund – to take the place of the Lottery-financed fund wound up in 2006. This will enable more communities to opt for ownership. A review of the Land Reform Act's workings, as promised in last year's SNP manifesto, might be equally beneficial – especially if it led to the beefing up of legislation which, though symbolically important, has been of little practical value.

It would also be helpful if ministers in Edinburgh and London stopped insisting on selling state-owned land to communities at market value – something Michael Forsyth, who wanted such land to go into community ownership at next to no cost, was dead against.

So there's plenty Salmond and his colleagues can do to get another half-million acres into community hands. And if a Gigha visit isn't on his agenda, what about a trip to Scalpay, off Harris's east coast? Scalpay's landowner, London restaurateur and businessman Fred Taylor, is offering the island to its residents free of charge because he thinks the spread of community ownership is opening up what he calls "a new area of democracy".

"I hope that community ownership takes off more and more," Taylor tells me. "I hope the Scottish Government helps as much as it can to make this possible."

Perhaps Alex Salmond could find out when Taylor is next going to be on Scalpay. Since he's shown willing to give his piece of Scotland to its inhabitants for nothing, it would be good if the country's First Minister were to drop in to say thank you.