'Tax haven' may increasingly be a term of abuse but for multinationals, they remain extremely popular places to have subsidiaries. With their low tax rates and high secrecy, their financial benefits outweigh their reputational risks.
This is clear enough from a glance at companies in London's FTSE100, all but two of which have subsidiaries in what they probably prefer to call 'offshore financial centres'.
But just how much is it worth to have a branch somewhere like Mauritius, the British Virgin Islands or Switzerland? New research by Christian Aid suggests that the answer is 'a great deal'.
When we used the Orbis database on private companies to analyse the finances of 1,500 multinational corporations operating in India, we found that those with links with tax havens paid 30 per cent less in tax than those with no such links. For a multinational with a multi-million dollar tax bill, this could be a multi-million saving.
There is no mystery about how this happens. As has finally become clear to politicians, campaigners and citizens everywhere, multinationals have become adept at shifting their profits out of the countries where they were made and into tax havens. For examples, look at how the likes of Amazon, Google and Starbucks have paid stunningly little corporation tax in the UK.
They do so by setting up subsidiaries in tax havens and then claiming that those subsidiaries provide some valuable service to other parts of the multinational. So valuable, in fact, that it supposedly justifies those other parts paying huge sums to the tax haven subsidiaries. No wonder, then, that the other parts of multinationals are left with only tiny profits left to tax.
This is all very well for company bosses and shareholders, whose rewards presumably grow as their tax bills shrink.
But who pays the price of their miniature tax bills? The answer is the people at the other end of the wealth spectrum, who need public services funded by tax revenues - schools, health clinics, police services and in some countries, food to stop them starving.
Around the world, hungry people remain a shockingly large minority. One in eight people - some 868 million - go to bed hungry every night, according to the UN's Food and Agriculture Organisation. World progress towards tackling hunger has been disappointing, especially in Africa, where the number of children, women and men undernourished grew from 175 to 239 million between 1990 and 2012.
But with tax justice, governments in developing countries could obtain more than the extra US$50.2bn (£32bn) needed annually in order to end hunger by 2025 (the figure is cited by the FAO in its State of Food and Agriculture 2012). This is the key message of Christian Aid's new report, 'Who pays the price? Hunger: the hidden cost of tax injustice'.
Tax is today the most predictable and sustainable source of finance for governments. Yet the poorest countries collect an average of only 13 per cent of their GDP in tax revenues, compared to around 35 per cent in wealthy countries.
There are several reasons why developing countries are unable to raise tax revenues, such as the abusive use of tax incentives to attract foreign investment. However, one of the most important factors is tax dodging by multinational corporations.
Which brings us back to their use - and abuse - of subsidiaries in tax havens. The ease with which multinationals can avoid paying their fair of tax is staggering. And it reflects what the OECD said in its February report about 'base erosion and profit-shifting' - that the current international rules on how multinationals are taxed, first drawn up 80 years ago, are no longer fit for purpose.
The rules assume that multinationals' subsidiaries buy and sell products and services between themselves at the same prices as if they were independent companies. But this is clearly not the case: multinationals today arrange their affairs to minimise costs and maximise their overall profits.
So the world needs new rules that reflect how multinationals really work now. And any change to the current tax rules must enable all countries, including developing ones, to obtain their fair share of tax.
Tax justice can be a very powerful weapon against poverty and hunger. But such transformations are unlikely, if developing countries continue to be excluded from the talks about how the world tax system should be redefined.
What we need now is political leaders who are ready to take determined action - not only to define fairer tax rules but also to tackle the financial secrecy some countries offer that enable tax dodgers, corrupt officials and criminals to hide their ill-gotten money from the authorities.
The UK government, as Chair of the G8 in 2013, has a golden opportunity to lead by example It should begin by requiring the UK's tax havens - its Crown Dependencies and Overseas Territories - to immediately sign up to the existing treaty on exchanging financial information with other governments. That would give tax dodgers and corrupt individuals fewer hiding places. It should then persuade the G8 to initiate a new international treaty, requiring every country to publish details of who really owns the companies within their borders.
Such reforms would make a tremendous difference to people across the world - and would amount to a G8 of which the UK could be extremely proud.