America is run by the rich and powerful in their own interest. To an extent that I think is hard to exaggerate, the intellectuals - academics, journalists and so on - are bought off. And that's a big change that happened in the United States in the last 30 or 40 years.

Poverty persists, essentially, because the people at the bottom - the bottom quarter and also the bottom half - see the gains from the rising global average income wiped out by severe declines in their relative share.

A few hundred years ago, perhaps 85 or even 90 percent of humanity lived below a standard of living that today only 40 or 45 percent fail to reach. But at that earlier time only part of this poverty could have been eradicated, and this at substantial cost not only to the pleasures of the affluent, but also to their well-being and to human culture. In our time, nearly all severe poverty could be eradicated at a cost to the affluent that is truly trivial.

In 88 poor countries for which we have data, in each and every one of the 88, the PPP for food shows that poor people can buy less food than you would expect from the PPP that the World Bank is using. The reason for this is obvious on reflection. It has to do with the fact that most foodstuffs are tradable commodities: basic foodstuffs, such as rice, flour and beans, can easily be conveyed across national borders and their prices will therefore roughly mirror the exchange rates among currencies.

Some of the developing-country governments and populations are tired of having things rammed down their throats, but we're not yet at the stage we want to get to, namely where the developing countries join forces with one another on behalf of creative alternative ideas about how to take things forward.

The bottom half of humanity is living in severe poverty; not all of them are malnourished or severely deprived now, but they are extremely vulnerable to even small upsets in their income or in the prices they face of basic necessities, and when something like this happens, they can be thrown off kilter in terms of a disease of a family member or a change in food prices; anything like that can throw them into destitution.

We have this highly irrational system of incentivizing innovation for clean and green technologies, where we allow the innovator to have a temporary monopoly and then mark up the price of the product or sell licenses at high prices to those who want to use the kind of product that the innovator has invented. This system is collectively irrational because many people, to avoid the inflated prices of still-patented cleaner and greener technologies, opt for some older technology that is much more polluting.