I'd like to thank Jay Hanson for taking the time to write an
intelligible message that makes sense in places. That's not to say
that I agree with him, but at least we can now carry on a discussion.
I wrote:
> >I'd like to write a program to run a simulation of the world economy,
> >first to see if Jay's conclusions follow from his own data, and then
> >to do a sensitivity analysis to see what are the most important
> >variables.
To which Jay replied:
> I will save you some trouble Douglas, the most important variable is
> ENERGY. Economists are trained to believe that the world runs on money --
> but they are wrong. In fact, the world runs on energy. ...
This is rhetoric, and not particularly helpful. It makes no sense to
say the the most important variable is energy -- even if energy is
very important, as it is, it isn't a variable.
I think I should have explained a bit more about variables and
sensitivity analysis. Simulations use a lot of educated guesses or
estimates for certain values. Something cannot be used as a variable
unless it is defined well enough to estimate. If I asked Jay or
anyone else to give me an estimate for energy I'd be asking an
question impossible to answer because it lacks any specificity.
On the other hand, I could ask for an estimate of the amount of fossil
fuel available for recovery, or the rate at which fossil fuel is being
consumed, even though these questions are still somewhat vague,
because they are specific enough for an initial estimate.
Once the model is constructed it is easy to see the effect of changes
in those estimates, and we can try a range of values for each variable
in turn, thereby indicating which ones are most important -- this is
termed sensitivity analysis. Very often it turns out that apparently
important variables don't matter as much as people thought.
Once we've done the sensitivity analysis we can then see which
estimates are important enough to merit revising.
It might well turn out that the amount of fossil fuel remaining is not
nearly as important as was thought because it effects only the date of
the predicted calamity, not the magnitude of it. Or it might turn out
to be vitally important, if a larger amount could give us enough time
to invent our way out of the problem. If it does turn out to be
important, then spending the time and money to get a better estimate
might be worthwhile.
I should thank Jay for one very positive contribution to this effort,
the explanation of an important factor, the "energy price" of energy.
That's too variable to be one variable, if you'll pardon the
expression, but we could try to get an estimate for it today and an
estimate of how it will increase with time.
It's probably better to break it down a bit further, perhaps by the
type of energy source. Whether you measure it by money or energy, the
cost of oil is almost certain to rise, eventually, as supplies run
out, but some other costs may fall. Currently solar power is
expensive, but it is not unreasonable to suggest it will cost less in
the future.
I think most of us already understand the meaning of 'nonrenewable
resources' and 'fossil fuels', which Jay has taken the trouble to
again yet again, and I think most of us who do envision the survival
of our species assume that at some point we will use other energy
sources, such as solar energy or thermonuclear fusion. What matters
may well be timing.
Personally I'm optimistic about various forms of solar power, which
I believe could be developed with existing physical technology --
though we lack the social technology to commit ourselves to it,
but I ignore thermonuclear fusion, which I'd rather we didn't try
to exploit for the foreseeable future.
I'll try to find a way to include such complicated matters in my
model, but it won't be easy. And that's really what's wrong with
Jay's argument. He is absolutely certain beyond a shadow of a doubt
that we're just going to run out of energy, period, while I find it
hard even to begin estimating such things. What does he know that
I don't?
That last line leaves me open to a cheap shot, Jay, but I'd rather
you tried to answer it seriously. You tend to talk down to people
in your messages, as if we were all rather stupid people who've
never heard of such amazing concepts as nonrenewable resources or
fossil fuels. I would suggest instead that the subscribers to this
list are on the whole unusually intelligent and well-educated people,
at least as intelligent as you, Jay, which should give you cause
to reflect. What DO you know that the rest of us don't?
dpw
Douglas P. Wilson [EMAIL PROTECTED]
http://www.island.net/~dpwilson/index.html
