This week's Economist has a really nice section on the growth of inequality (click here). Many parts of the developed (and emergent) world have experienced growing wealth and income inequality over the past three decades. My own work on Ireland shows that wealth in the 19th century was concentrated in the hands of the top 1% of the population, but from 1900 onwards wealth became less concentrated. However, since the 1980s, wealth has become much more concentrated. The big questions arising from this for economists and other social scientists are why has this happened and what can we do about it?
The Berkeley Earth Project , an independent study of global warming, has found that the earth has become a degree warmer over the past half century. However, the statistical uncertainty surrounding pre-1920 estimates makes it very hard to say much about long-term trends - click here for graph . This is one of my concerns with the global warming debate - we simply don't have trustworthy long-run data which looks at temperature changes over the last millennium (or two). My second concern with the global warming debate is that it is very hard to prove any sort of casual link between global warming and human activity. The scientists may be able to show correlation between global warming and our production of carbon dioxides etc., but correlation is not causation. My third concern with the debate is that those who are sceptical or agnostic are stereotyped as flat-earthers or intellectually-challenged crackpots. This only stifles debate and the progress of science itself.