[p2p-research] List of articles on Indium/Gallium Supplies

[marc fawzi]

If you look at the data, the author points out the fact that the URR
[ultimate recoverable resource] is much higher than his estimate
(which is based on the USGS production data alone) in case of Gallium
but he decides not to includes the reserves base because he mistrusts
the accuracy of the reserves data, which are also supplied by USGS,
citing "high uncertainty of the data for gallium."

By deciding to use the production data alone all he is able to predict
is the depletion (or rather the "collapse") of production, not the
depletion of gallium itself. There is one humongous difference here. I
hope you understand.

He says that "In principle, the peaks that we have reported could be
interpreted as due to factors other than depletion."

(sorry but I personally find it funny)

How can you predict depletion of a resource based on production data alone?

Furthermore, the application of logistic regression to survey data
itself (to predict collapse of production) is not exposed in the
article and could contain some crucial errors, i.e. where is the SAS
model or where is the model design in general?

For example, if the production volume shows periodicity where the
period is known then that takes a different kind of logistic
regression model than if the period is unknown, and yet another model
if it's non-periodic. So I am not sure if he's applying logistic
regression correctly (for collapse of production) given that I don't
see the calculation.

This also implies that by not discussing the possibility that the
production volume (the detailed data not the cumulative data) may be
periodic his prediction of the collapse may not only be entirely
flawed (in the design of the logistic regression model) but also
obstructing a significant truth about production data in ecology and
mineralogy, which is that production peaks and collapses in periods
(up to the Feigenbaum constant, i.e. r < 3.6) and then it goes into
chaos.

What causes the periodicity and eventually chaos is that the
production rate exceeds the sustainability limit for the given
production technology and/or the sustainability limit of the market
(he does not supply demand as another possibility rather than
depletion of the resource) so production collapses but that doesn't
mean resource is not depleted. The production grows again when more
efficient technology is developed for extraction or when the market
swings back into demand mode (from over supply.)  In fact that is what
may be happening with oil, too. We're reaching the first point of
bifurcation (the point at the which the quantitative behavior of the
system changes abruptly)  but it does not mean that more efficient
technology won't make deep oil reserves cheap again which will cause a
come back in oil production (after the collapse).

The analysis given by that paper is silly at best.

Marc




On Wed, Feb 25, 2009 at 2:58 AM, Tere Vadén <tere.vaden at uta.fi> wrote:
> There is some quantitative analysis here, as regards Gallium ("According
> to a logistic fit of the data, it peaked in the year 2000 (Fig. 5)")
> (and other minerals) though not explicitely related to solar:
>
> http://www.theoildrum.com/node/3086
>
> marc fawzi wrote:
>> I have not seen a numerical analysis of the "time and scale" problem
>> as it applies to solar energy.
>>
>