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.

Each powerful player, or coalition of players, will make concessions in areas where it has relatively less at stake in exchange for other such players making reciprocal concessions in other areas where it has relatively more at stake. Such trades are collectively rational insofar as they get each of the powerful players more of what it wants. But such trades are also dangerous because the whole international rule-system will become incoherent and therefore vulnerable to crises that will continue to become increasingly severe.

To improve global health, it's not enough just to have a really good new product and to obtain marketing approval. You still need to market the product and bring it to patients, follow up, create the infrastructure, and so on - the whole pipeline, the network. That's something that companies are extremely good at: organizing a whole pipeline in a cost-effective way.

Given the total income and wealth available in the world today, we could easily overcome poverty, which would require raising the share of the bottom half from three to roughly five percent. Unfortunately, the trend is going in the opposite direction.

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.

Our global institutional arrangements - the basic ground rules that govern our world economy - are human-made. They don't exist naturally, nor are they God-given. We make these rules, those of the WTO [World Trade Organization] Treaty for instance, which fill tens of thousands of pages. These words have been strung together by human beings and are also interpreted and enforced by human beings.

There is at the global level a very small number of actors who can meaningfully weigh in on global institutional design, who are able - through powerful governments and most effectively through the government of the United States - to exert substantial influence on international negotiations, which are routinely conducted behind closed doors.