By using general consumption PPPs, the World Bank is, in effect, saying to the poor: "Sure, you cannot buy as much food as the dollar value we attribute to your income would buy in the United States. But then you can buy much more by way of services than you could buy with this PPP equivalent in the United States." But what consolation is this? The poor do not buy services - they are services, on their luckier days.

Purchasing power parities are not a reasonable method for comparing households across countries or currencies. The reason for this is simply that PPPs are sensitive to the prices of all the commodities, goods and services, that households are consuming worldwide, with each commodity weighted in the calculations according to its share in international household consumption expenditure.

You can think of the Health Impact Fund as a mechanism that would keep the benefits and burdens of pharmaceutical innovation for the affluent roughly as they are while massively reducing the burdens presently imposed upon the poor. This sounds like magic. But it really works because the current system is not Pareto efficient. It's a system that generates hundreds of billions of dollars in litigation costs and deadweight losses that HIF-registered medicines would sidestep. By avoiding these losses, the HIF reform can bring improvements all around - including for pharmaceutical innovators.

This splendid book discusses how, in the last two hundred fifty years, large numbers of people have achieved levels of well-being that were previously available only to a few individuals, and how this achievement has given rise to equally unprecedented inequalities. Unique in its focus and scope, exceptional knowledge and coherence, and careful argumentation, The Great Escape is highly illuminating and a delight to read.

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.

It is perfectly consistent - and also true - to say that the world poverty problem today is smaller (relative to world population) than before and yet also a much graver injustice.

In order to prepare for meaningful change, we have to look at both sides of the problem. We need to examine the output of our political system, which is often very hostile to the poor abroad and hostile also to the poor and middle class domestically. And we must also look at the procedures through which this output is produced.