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On 2016-05-16 07:03, Dan TheBookMan wrote:<br>
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cite="mid:CACB7g25tyyTPWfH=kDxPZY8jRozj07ox3nbsTzyBEsEHt76+2g@mail.gmail.com"
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<div>On Fri, May 13, 2016 at 12:37 AM, Anders Sandberg <<a
moz-do-not-send="true" href="mailto:anders@aleph.se"><a class="moz-txt-link-abbreviated" href="mailto:anders@aleph.se">anders@aleph.se</a></a>>
wrote:<br>
> On 2016-05-12 21:41, Dan TheBookMan wrote:<br>
> "While I wouldn't want to risk it, my guess is other
folks in the chain of command<br>
> would likely not follow orders. However, let's set that
aside. Let's say you're right:<br>
> Trump in office would increase the odds of a nuclear war.
By how much? Maybe<br>
> Caplan is right about the overall 2.5 times risk. Let's
say 2.5 times whatever the<br>
> base rate would be or, better, than Clinton or Sanders.
(My guess is Sanders<br>
> would be less bellicose than either Trump or Clinton.)<br>
><br>
> You can estimate the base rate by doing a Bayesian update
on a uniform prior<br>
> [0,1] of nuclear war probability per year, given 70 years
of no war. That gives<br>
> you an expected 1.4% risk per year.<br>
><br>
> If we accept the 2.5 increase, that means 3.5% risk per
year. Over 4 years that<br>
> is 13% risk of a nuclear war (compared to 5.4% for normal
presidents).<br>
<br>
</div>
I think that estimate is too high. Caplan's view is for a major
war -- not necessarily a nuclear war. I think we'd have to
include another term to determine what the rate of any major war
turning into a nuclear one. But let's run with it.<br>
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<br>
One can use Martin Hellman's Markov chain model: you have states of
[peace], [international crisis], [major conflict] and [nuclear war],
and transition probabilities between them. <br>
<a class="moz-txt-link-freetext" href="https://www-ee.stanford.edu/~hellman/publications/75.pdf">https://www-ee.stanford.edu/~hellman/publications/75.pdf</a><br>
<br>
How many years of international conflict have we had? If we use the
20th century and make it all UScentric we had at least two conflicts
(WW I and WW II), lasting in total 9 years and with a transition
risk to peace of about 0.2 per year. One might add the Korean War,
where nuclear attacks were considered. I think assuming a 1/4 risk
of nuclear attack in a direct power conflict is not crazy given WW
II, but lets say 1/5.<br>
<br>
Not certain how many years should be regarded as international
crisis years. Looking at <br>
<a class="moz-txt-link-freetext" href="https://en.wikipedia.org/wiki/International_crisis">https://en.wikipedia.org/wiki/International_crisis</a><br>
suggests that the US was involved in the Berlin Blockade, the Cuban
Missile Crisis, the Pueblo Incident, the 1973 Chilean coup, Ace
murder incident, the Iran hostage crisis, and Able Archer. These,
plus the two major wars, suggests a probability of about 0.09 per
year of a crisis happening, and then about 0.2 risk of war. We had
at least 2-3 crisis situations that nearly caused nuclear war, so
that transition arrow from crisis to war is about 0.02 or 0.03. We
also had two cases of internaiton<br>
<br>
peace -> crisis 0.09<br>
peace -> peace 0.91<br>
crisis -> conflict 0.2<br>
crisis -> nuclear 0.02 <br>
crisis -> peace 0.78<br>
conflict -> nuclear 0.2<br>
conflict -> peace 0.2<br>
conflict -> conflict 0.6<br>
<br>
The transition matrix becomes:<br>
<br>
<pre>[0.91 0.09 0 0</pre>
<pre> 0.78 0 0.2 0.02</pre>
<pre> 0.2 0 0.6 0.2</pre>
<pre> 1 0 0 0]</pre>
<br>
Note the debatable model that peace occurs after nuclear wars (the
last line is [1 0 0 0]). In any case, the model predicts the
following distribution: peace 87% of the years, crisis 7.8%, war
3.9% and nuclear war 0.93%.<br>
<br>
One can also make nuclear wars a final state, [0 0 0 1]. I have a
paper (in writing limbo, unfortunately) on the correction factors
due to anthropic selection - if there are no survivors, then you
cannot ever observe a nuclear war in your past, so the transition
probabilities would be biased in a nontrivial way. It can be
corrected, and then near-misses like the Petrov incident give some
information. Right now the conclusions look rather reassuring, but
that might simply be because nuclear disasters are somewhat
survivable (if they just kill half of the observers you get a 2/3
bias). <br>
<br>
If one buys the xrisk model instead, the time spent in peace in this
post's model is 88%, crisis 7.9%, and war 3.9% - in this particular
case there is actually very little change. <br>
<br>
This model also supports the conclusion that the nuclear war risk
per year is on the order of a percent. <br>
<br>
Clearly real-world data gives us reasons to update the current level
of concern in different ways, but this represents a large scale
"outside view" of a century. Obviously one can tinker with the model
and especially the transition probabilities endlessly. But I think
the results will not be astronomically different.<br>
<br>
<br>
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<div>> Now, what can you do about this? Panic? Build a bomb
shelter? My guess is<br>
> very little aside from get worked up."<br>
><br>
> Move to Tasmania?<br>
<br>
</div>
<div>Bouvet might be better. :/<br>
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<br>
4 days of sunshine per year? I will take Tasmania any time. Even
Kerguelen. <br>
<br>
(My dad had a minor obsession with the island, and there is actually
a map of it hanging in my room. Mostly ice, with the volcanic
beaches inhabited by penguins and seals. Not the most hospitable
place. )<br>
<br>
<br>
<pre class="moz-signature" cols="72">--
Anders Sandberg
Future of Humanity Institute
Oxford Martin School
Oxford University</pre>
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