Business as not usual

I ventured from the science pages on the Guardian website on Friday by commenting in a piece about the change in energy prices here. I was asked to look at a time series data set of wholesale prices and price to the customer. I did a very basic analysis by separating the time series into the trend, seasonality and noise using a mulitplicative model. I did this with the gas and electricity data and it showed some pretty obvious behaviour. In the main everything has an upward trend, to be expected with some minor deviations which I'm sure an economist can point at with specific causes. The seasonality effects are smaller for the customer than the wholesale but there is a clear bias towards customer increases rather than decreasing when comparing between plots. A simple regression on the trend indicates diverging costs but I'm sure there are lots of details that could be taken in to account. Basically, in a non-academic non-rigorous kind of way, it reasonable to comment that the curves for customer get a worse deal than those for wholesale. Saying that though, I'm sure there are things not captured by this data that need to considered to really make hard statements about overall cost. For example, the consumer plots are smoother which I suppose is for a practical reason. There'd be a good proper research project in all of this...