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.

To make a proper moral appraisal of the prevalence of severe poverty today, we should focus not on comparisons with times past, when the global average income was much lower, but on a comparison with what would be possible in our time, given the current global average income and level of technological and administrative development.

Feudalism is an economic system where a few people own all the land and the others have no option but to be serfs on such a feudal estate. We now condemn feudalism. We condemn not merely the feudal lords but we condemn the whole structure of rules that sustained feudalism. I am asking people to think similarly about the world economy.

For the present system to work, poor people must be excluded from the innovation, because if they could get access at an affordable price, then affluent people would find ways to buy it cheaply as well - and then the innovator would be poorly rewarded and introductions of new medicines would decline.

Car prices play a large role in calculating PPPs even while they play no role whatsoever in the consumption or consumption needs of the poor. And the prices of rice, bread and beans play a small role in calculating PPPs even though they play a huge role in meeting the consumption needs of the poor. So the World Bank's method of comparing and converting everything at general purchasing power parities into US dollars is highly distorting within an exercise whose purpose it is to determine whether households are or are not capable of meeting their basic consumption needs.

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.

Severe poverty is getting better by some measures, but it's also becoming ever more scandalous because it is now so easily avoidable.