Alistair Darling may have all the charm of a broken ankle but it was hard not to feel a little sorry for the poor fellow this week.

After his humiliating climbdown on capital gains tax, he had to concede that yet another of his flagship proposals from the autumn PreBudget Report, the taxation of so-called nondomiciled residents, was equally ill-considered.

But while the Chancellor was right to compromise on his plans for additional disclosure and retrospection, there should be no more concessions to the nondoms. Amid all the hullabaloo about an exodus of half the City to Switzerland, perspective seems to have been lost. The simple fact is that the tax status that nondoms currently enjoy is both unneccesarily generous and unfair to resident taxpayers. Labour’s £30,000-a-year levy is not unreasonable, particularly when considered against the Tory party’s proposals, which would raise six times as much revenue.

It is also a nonsense to suggest that the modified levy is a threat to London’s status as a leading financial centre. For a start, the tax does not even apply until a nondom has lived in the UK for seven years. Once you have been somewhere for that long, you are almost part of the furniture and unlikely to up sticks at a moment’s notice. It is just not credible that thousands of nondoms are about to move to Switzerland, Dubai or anywhere else. Swapping countries is simply not practical or desirable for many nondoms because they rely on the back-office infrastructure and enjoy the cultural opportunities that London provides.

Some nondoms try to justify their advantageous tax position on the ground that they do not use public services such as health and education. This, of course, is complete hokum. An ambulance would still turn up if a nondom were hurt smashing his Ferrari into a wall in Kensington. The police would still turn up if a nondom were to suffer the misfortune of a late-night altercation with a hoody in Chelsea.

Taking a slice of long-established nondoms’ yearly income is not the politics of envy; it is sensible, reasonable and fair. Nobody likes tax but all must pay their share.

The benefits of going green are not black and white

Admittedly it was a wholly unscientific study, but Times Money has calculated that it costs, on average, an extra £2,500 a year to become a do-gooder; that is go green, ethical or organic with your food shopping, mortgage, savings, credit cards, investments and energy.

For most people this is a lot of money. So the question has to be asked: is it really worth it?

Well, when it comes to organic food, it is far from clear whether you are paying a premium for real quality, or just the perception of such. There are also questions about whether organic is actually better for the environment. Organic milk, for example, generates more carbon dioxide emissions than conventionally produced milk and uses up 80 per cent more land. Similarly, having a locally grown organic box of vegetables delivered to your door can be more damaging to the environment than buying produce from farther afield. Why? Because the bulk haulage of food over long distances often produces fewer carbon emissions per unit than locally grown produce.

Similar doubts surround some green energy tariffs. The big energy companies are required to meet government targets on the amount of energy they generate from renewables. In many cases, the suppliers just repackage and market this renewable energy as a green tariff, often charging a premium to the customer into the bargain. The sad reality is that signing up to these tariffs can make no difference to total carbon emissions.

Green or ethical mortgages, credit cards and savings accounts may offer more practical benefits, such as planting trees, but borrowers or savers with a conscience would almost always be better off finding the cheapest deal and donating the saved cash to their favourite cause. Even so-called socially responsible investments may not be that ethical or that green. Last year, research by Trucost, a research group, found that a quarter of ethical investment funds have a higher carbon footprint than their more mainstream rivals.

It’s clear that the benefits of going green are not always black and white. Buyer beware.

New moves by BT to save the planet will cost you the earth

Had Milton Friedman dedicated his life to telecoms rather than economics, he would probably have noted that there is no such thing as a free phone call. Particularly if he was a customer of British Telecom.

This week millions of people on the former monopoly’s Option 1 call plan received letters boldly proclaiming that weekend calls were now “free”. Cue widespread rejoicing across Britain? Not for anyone with the good sense to read a little farther down the letter.

With considerably less fanfare, BT also explained how daytime and evening call charges will rise. Industry experts expect this price restructuring to net BT extra revenue.

Worse still, in April, an estimated nine million BT customers who receive their bills in the post will see their line rental increase by 75p a month to £11.75. This cleverly marketed move to help the environment by encouraging online billing will net the telecoms giant an estimated £80 million in extra revenue each year.

“Saving the planet” and offering “free” calls has never been so profitable.