Hamish McRae: For sale: everything in Britain

Yesterday the path was cleared by the Competition Commission for bids to be put in for the London Stock Exchange - though with some conditions that may put bidders off. A day earlier the Spanish telephone group agreed to buy O2, the mobile phone operator founded by British Telecom, leaving Vodafone the only British-owned mobile service in the UK.

That day too glass-makers Pilkington said they had been approached by a Japanese company with the aim of making a bid; P&O, the shipping group, said it has been approached by the Dubai port operator; and someone is apparently trying to buy house-builders Mowlem.

Now you could say: what's new? We sold off our entire motor industry, including Rolls-Royce and Bentley. We sold all our merchant banks. Electricite de France supplies a quarter of British homes with power. Foreigners buy our most expensive houses, while Russians don't just buy homes in Chelsea - they buy football clubs too.

So this process has been going on for a long time; so long that we regard it as normal. This week is just seeing a new burst of it. But that itself is remarkable, for this openness is not nearly so evident in other developed countries. In France and Germany there are all sorts of barriers in the way of foreigners seeking to buy assets. Even in the US there are restrictions that do not exist in the UK: foreigners cannot take control of US airlines, for example, though thinking about that one, I'm not sure many would want to do so.

This unique position in the world raises two questions. The simple one is whether it is a good idea to be so open. The more complex one is if Britain is the most extreme example of an open society - at least in economic terms - what does our experience say about the ways in which the global economy is developing?

On the first, many of us feel intuitively uncomfortable about some aspects of the "everything for sale" sign on the country. I don't think people wept many tears about the sale of Rolls-Royce and Bentley, or even the rump of Rover ending up owned by the Chinese. But there has been some soul-searching in the City as to the long-term implications of having such a large portion of the financial service industry owned abroad.

It is the country's largest and most successful industry, pays some of the highest salaries in the world and earns enough revenue to cover much of the trade deficit. But in theory at least, if the foreign owners wished to repatriate the business to New York, Frankfurt or Paris they could.

There is a social dimension too. It is not just that foreign-owned companies will seek to run things their way, though this occasionally leads to conflict, witness the events at Gate Gourmet. It is also true that foreigners working here have special tax treatment. One of the reason why they can pay so much for their London homes is because in general they pay less tax than the equivalent Briton.

But while we have undoubtedly lost some national control of key industries, I think it is pretty generally accepted that there is a huge net gain for the country. Some industries are run better by foreign owners: BMW may have failed with Rover but they kept the Mini, and the Oxford factory at which it is made is the most heavily used assembly plant in Europe. London has increased its already dominant market share in the financial service business thanks largely to becoming the European base for the international banks.

That would be hard to dislodge. A company can quite easily shift manufacturing production to China with a bit of investment. But in financial services the capital is human, not physical, and moving that would mean shifting tens of thousands of people.

The financial sums also work in our favour: last year we earned £140bn from our overseas assets, much more than we pay out on assets owned by foreigners here.

And what of the Roman Abramovich factor - the cultural implications of foreign influence? Well, while there are losers from the influx of foreign talent and money to the UK, I should have thought that on balance again we are net winners by a large margin. The country has certainly been livened up, though perhaps not always in quite the way we might choose.

But this in a way is the known debate. For better or worse we made a series of policy decisions to open up our society, including the "big bang" City reforms of 1986, deregulation of many previously state-owned industries and a pro-competition and anti-protection approach to take-overs. There may have been costs to becoming so open but we have done it and that is that.

What then does this experience say about the world? I suppose the starting point is to acknowledge that globalisation means specialisation. Superficially the world looks more similar. Go to Shanghai and the new buildings look like a slightly coarser version of those in Chicago. The brand names in the shopping centres are either the same as those in London or Paris, or a rip-off of them.

But that is just the outside. If you look at what countries are actually doing to earn their livings, there are ever-greater differences. More than ever before, countries are doing what they are best at, leaving the rest to others. Take manufacturing: as a general rule, the developed world is increasingly doing design and marketing, while the goods are made in places where labour is cheaper. An example of that is Dyson's iconic vacuum cleaners, now made in Malaysia.

In services the lower-skilled jobs are being shifted offshore where possible, while the higher-skilled ones are being retained and enhanced at home. If there has been less progress in this, it is because many services can be derailed by cultural and language barriers - as anyone who has spent a fruitless hour on the phone to Bangalore trying to get their phone service sorted will recognise.

So we see this process of specialisation just about every minute of our lives. The key point is that by being more open to international influences, including foreign takeovers, the UK has become more specialised than any other large, developed country. In proportion to our economy, we are more owned by others. But proportionately we also own more abroad. We do this in human capital as well as corporate capital, with nearly one third of our 100 largest companies headed by a foreigner. We have become the test-bed for globalisation. Putting the London Stock Exchange up for sale is just one step on that march to an ever-more interdependent world economy.