In every country, rich or poor, the story is the same. There are not enough nurses. The developed world fills its vacancies by enticing nurses from other countries, while developing countries are unable to compete with better pay, better professional development and the lure of excitement offered elsewhere.

Poor sanitation helps spread disease, yet efforts to provide subsidized toilets have been resisted for cultural reasons in many developing countries. To improve the rate of uptake, some people are now advocating a market-based approach.

The potential impact of climate change was highlighted at the recent United Nations Climate Change Conference (Dec 3