It is irrational to charge high prices for socially valuable innovations as this guarantees that they will be underutilized. It is much better to sell them at cost and then to reward the innovator in some other way. This is not always possible, because in some cases the value of an innovation is in the eye of the beholder; it's very difficult to value how much a new Madonna song is worth, for example. But in the case of medicines, green technologies and seeds in agriculture, such an alternative reward mechanism is fairly straightforward.

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.

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.

Income inequality matters more on a day-to-day basis. Wealth matters more for political influence.

What we should do is require or at least permit innovators to license their green innovations free of charge in exchange for public payments based on the impact this innovation has on the environment - emissions averted or something of this sort.

We live in a world where economic positions - income and wealth - are very unevenly distributed, and this leads to the widespread persistence of poverty.

The extremely low respect Congress enjoys among the population indicates that the citizens understand broadly what's going on. But the lack of a realistic political reform path leads to apathy and the kind of mindless frustration that manifests itself in the Tea Party-style hatred of any and all government.