I
have been in a lot of major cities in my lifetime, and several of them have a
thriving diamond district. Click here to read an interesting take on why
diamond shops in most major cities tend to locate close to each other. The basic argument is that it lowers search
and information costs for diamond customers.
I am not sure if this is totally correct. Another possible reason why diamond shops may
locate close to one another is that by being close together, they lower their
joint security costs. Given the density of
diamond shops in one area, one would expect more cctv, police patrols etc.. Notably, all of the major diamond shops near
Hatton Gardens in London are two minutes away from the nearest police station!
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.