Leading article: Just giving

The United States has proportionately more billionaires than Britain, in part because the income gap there is even wider than it is here. But that is no excuse for not embracing the idea of "The Giving Pledge", pioneered by champion investor Warren Buffett and the Microsoft founder, Bill Gates. It was launched barely two months ago, and there are already almost 40 American billionaires signed up to dispensing at least half of their fortunes, either during their lifetimes or after death. In this age of austerity, there seems to have been something in the Buffett-Gates challenge that appealed to the country's super-rich.

Granted that philanthropy has nothing like the following here that it does in the US; granted, too, that our tax incentives for personal charitable giving are inferior, the principle is nonetheless the same. Half of one billionaire's fortune is a lot of money; half of 10 billionaires' fortunes is 10 times that. And the written statement of intent can usefully concentrate even a billionaire's mind. For all that, the proof of the pledge is the action. As described by Buffett and Co, the pledge is a moral commitment, not a legal contract. It's worth keeping an eye out to see whether, when the time comes, moral pressure is quite enough.