I was saying that even a perfect substitute that does not have to volume to moderate prices probably has no more effect then partial substitution on the extraction or exploitation pressure of the original resource.

For oil all I'm saying is that as long as prices remain high we will extract at the highest rate we can. Certainly above ground factors influence how close we get to the maximum rate but the pressure if you will is not relieved on the desire for the original resource. Only substitutes perfect or not that can replace a substantial amount of the original resource are capable of moderating prices and thus extraction pressure.

With out this substitutes only serve to keep demand stronger for longer as they delay the move to simply stop using a resource either the original or a substitute. So in my opinion only a fundamental change away from a resource or a valid significant substitution can really change the exploitation pressure on a resource.

As far as drilling more wells well that increases the depletion rate just like sending out more boats increase the depletion rate. You don't get more oil drilling more wells but your certainly extracting it faster. In the case of sturgeon this resulted in collapse. I've been saying for some time that the potential for the same sort of collapse exists for oil extraction.

The sturgeon example shows it possible. So the question should not be if its possible or not but does oil extraction fit the sturgeon example. Whats fascinating is that the dynamics of this sort of collapse.

I googled to see if anyone had numbers on the number of boats actually fishing for sturgeon but this is probably hard to get since a lot of the fishing is illegal. My best guess is that after fishing pressure reached a certain level the actual number of boats out fishing did not change all that much and the stocks collapsed under a constant but unsustainable fishing pressure.

For oil the thesis is we have gotten efficient at extracting the resource we are not extracting far faster then we can bring new fields online and in most regions we effectively have no more reserves to extract.

The decline in production is now tied to the depletion rate as fields cannot be replaced.

Back to sturgeons I suspect what happened is the fishing fleet grew large enough to take 10% of the initial sturgeon population a year. This was way beyond replacement rate and in 10 years no more sturgeon.

For oil the focus in on smaller fields with lifetimes of 5-20 years. We hit the maximum rate we could exploit these say back around 1990 or so we depleted the number of small fields undeveloped at say a rate of 10% a year and given the lifetimes of the fields about 10-20 years later having run out of "stock" production collapses.

Oil is certainly different in the sense we have the large fields which hopefully will exhibit slower decline rates but in my opinion the way we have exploited our smaller oil fields is quite close to the sturgeon problem and should result in the same decline curve. Over the next 10 years or so this will probably have a bigger impact on overall oil production then the slowly declining large fields.

Feel free to look around the number of smaller fields approaching the end of their useful life is astounding and in general these fields undergo steep declines once they reach maturity. Every region I've looked at has most of its smaller fields either already in decline or rapidly approaching decline. This fits well with the sturgeon model of efficient constant exploitation with effectively no replacement until you simply had nothing left.