Tuesday, March 13, 2007

angry grumbles and HL

Predicting the Past: The Hubbert Linearization Robert Rapier
It is invalid to use three decades of hindsight for refining the Texas forecast, because we clearly don't have the same option with Saudi Arabia. Yet some argue that the Saudi peak can be forecast with confidence using the knowledge obtained from the case of Texas – a region in which the uncertainty of the method spanned almost 3 decades.
So, the HL has shown that it is good at forecasting the past, but can be very unreliable for predicting the future. In Part II, we will examine the evolution of the Saudi HL over time.

This is a line of reasoning that Mobjectivist has been tracing for years, although unfortunately Robert Rapier, posting on The Oil Drum, did not see fit to reference his work.

Already in a bit of a twist, I then read a few insufferable responses from Stuart Staniford. Below is my response, cross-posted to the Oil Drum article referenced.

Per claim in the Stuart quote, Rapier is NOT the discoverer of the inadequacy of Stuart's favored model.

Reading this thread, I also note that Robert Rapier fails to acknowledge the modeling contributions and similar objections of Mobjectivist (Web Hubble Telescope), a materials scientist who has been visible, active and rational in the small but growing peak oil community since May of 2004.

I'm more than scornful and less than impressed.

I've watched these threads before, as Stuart slavishly and continuously posts on a flawed technique, (One which big oil apologist Michael Lynch accurately describes as "curve fitting").

The atmosphere is so chilly towards Mobjectivist when he flatly debunks the linearization model, as he has done for well over a year, that some posters on these threads have grown confused and attacked him as if he were in opposition to the central thesis of peak oil - that is, individual reservoirs predictably deplete.

Sorry, no.

Rapier says, "Testing the model is called “validation”, or sometimes “back-casting.”"

Mobjectivist does this all the time, with multiple models. He has posted source code and equations over at his blog.

Robert Rapier, your references are incomplete if you do not acknowledge the ongoing work that Mobjectivist has done in this space.

Peak oil is something everyone has an opinion about, but at the core exists solid, empirical science. Science does not exclude ideas that are transparent and reproducible. Hubbert might agree, but it is time to stop appealing to his authority, for he is long dead.

I expect more rigor and honesty out of the subset of people in the peak oil community who have degrees which include the words "science" on them.

What are we, a cargo cult science? Hope not.

(Stuart Staniford) "I just want to add my support to Robert's great post. I agree that the key to understanding any prediction methodology is it's out-of-sample performance (...)
At any rate, I propose that we christen this phenomenon "Rapier Tail Creep" in honor of its discoverer :-)"


At 8:08 PM, March 13, 2007, Blogger WHT said...

All this stuff has so many levels of discourse. We have idiosyncratic human nature at work regarding the various analyses going on. And then we have the underlying unknowable grand model for global oil depletion that is governed by millions of individual monetary decisions. It's sociologically entertaining to watch this all unfold.

I myself sometimes forget that all we really amount to (at best) are big fish in a small pond.

At 9:48 PM, March 13, 2007, Blogger monkeygrinder said...

well, thanks for putting it like that,

unfortunately I hosed down the neighborhood over at TOD with a flamethrower without explaining why I needed to roast marshmellows in the first place.

Not letting RR or SS off the hpok they've both been active in these model discussions at TOD for many iterations.

At 9:56 PM, March 13, 2007, Blogger WHT said...

I don't know how a flamethrower will actually help. TOD is usually loaded with commenters possessing itchy trigger fingers. I usually don't blog during working hours, so I get there late and past-topic. It seems as if we are picking over the smoldering embers at this stage of the discussion.

You know one guy that never seems to get ruffled? That's Khebab.

At 4:02 AM, March 14, 2007, Blogger Big Gav said...

Nice post MG - good to see someone giving credit where it is due.

As for kebabs, they are my favourite way of ending a night out drinking.

And the other Khebab does do a fine job of modelling and collating everyone else's models.

At 5:44 AM, March 14, 2007, Blogger WHT said...

It's really fascinating how somebody like Khebab, who is doing this just as a sideline I presume, can make a difference in one of the most pressing issues of our time. I can't imagine that hobbyist global warming experts can make the same inroads for example. Not considering the big fish in the big pond like Al Gore involved in the GW debate.


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