Interesting point - as oil becomes more expensive, substitution may also become very expensive.I suspect we (as in the world ) will try and burn more coal post PO , but production in coal may decline as more expensive oil may lead to less coal productivity?
I suspect that we underestimate the effect of minor disturbances to our system ... and the associated ripple effects ...
There are some US discussion group posts talking about the increasing cost of asphalt and oddly the disappearance of carpet underlay ... due to the current oil price increases.
Carpet underlay is not vital - but when say tap washers, car tyres, rubber gloves or whatever start disappearing due to factory closures then life could get awkward.
Just imagine the firm making washing machine door seals closing down - there could be a suddent shortage of new machines and also problems in repairing duff machines too. All because of a minor knock-on effect of oil price increases.