On 8 February this year we noted that the European Union market for carbon dioxide emissions permits had crashed with prices per tonne below 3Euros.

As we noted then, arbitrage means taking advantage of the price difference between two markets.   I lived in Singapore for a while and travelled to Jakarta for work.   Return flights Jakarta to Singapore were less than half the price of return flights Singapore Jakarta.   Pre internet you'd get your mate in Jakarta to buy it for you.   With the internet no one can hide anything from anyone.

Here's Henry Ergas and The Australian's Rebecca Weisser discussing the crashing price that Europeans are prepared to pay for the non-delivery of a non-product to no-one.