Over the past decade increases in the price of copper have far outpaced those of aluminium. The flipside is that, during the downturn we expect over the next two years, we forecast aluminium prices to fall by only 10% by the end of 2013, while copper prices drop by 40% over the same period. The relative resilience of aluminium prices should also be underpinned by differing cost structures and demand substitution from copper to aluminium.