Its a good site – but it doesn’t quite give me the “why” behind what is going on. It is true that volumes are falling – but the specific reasons for the shift are not clear.

Thanks for the link – I had noticed that the Brent crude oil price was remaining relatively high. Even so – dated brent crude is under $40 a barrel.

Although construction may also be playing a role (I would put that down as a cost shock) the fact is that global petrol prices are as high as they were in late-October/early-November even though crude (even measured by dated brent) is at least down 40%.

When I try fitting it to different ARIMA specifications (using only data to 2000 to fit my coefficients) the last couple of month seem a touch out of place. Hence why I’m trying to fish out a bit of information.

I’m currently thinking that prices should come back in a couple of months time – even if crude prices don’t change (which is consistent with the article you linked to). But if there are other “structural” factors sitting around here I would be very interested in them 😉