The problem here is that we don't really know what this driving really is, what mechanism connects it to the GDP. The share of industry in the GDP has diminished and the share of the trucking also. This could explain the diminishing volatility.

This might be interesting if we were trying to find a new leading index for the GDP and use it for trading. But what it is we are now trying to find out relating to the Peak Oil? Will we try to see how effectively the oil prices affect the fuel consumption in the US? Then the answer is that they affect it a little bit but not much so far.

But this is not a good question. The Peak Oil is a physical phenomenon. So we might ask, how high the oil prices will go  when the supply goes down? Cutting the demand is easy in this situation - less oil, less consumption. But the price is only for allocating oil. It is not directly related to the physical supply. And the US is not alone in the world. Its share of the world oil use is only a quarter.

Would we like to know how diminishing oil supply affects the US GDP? We know already that it affects it. What we don't really know, is what happens when the oil supply diminishes for a long time - when world oil is in permanent decline.

Stuart is of course concerned with the oil efficiency of the US economy. But this is not the quite right question. It will not tell how the economy will behave. Highway driving is only one part of it. The total energy situation and efficiency is here the most important factor. The oil consumption statistics show that oil has been substituted for some extent. Changing lifestyle is much easier than getting more energy. Natural gas is now the real scare. Just move to electric cars if you could find enough power for that. Here we have the problem.