From derp to denialism

Over the last couple of weeks, I’ve seen four major reports (details over the fold) from very different sources, all making the same point: decarbonizing the world economy will involve economic costs that are
(a) small; and
(b) far outweighed by the benefits
And, the empirical evidence so far is strong. The EU and US have both reduced CO2 emissions significantly, at negligible or even negative economic cost. The measures announced by Obama, including vehicle emissions standards and restrictions on coal-fired power stations appear set to achieve further substantial reductions, again while yielding net economic benefits.

Against the expectations of doubters, wind and solar PV are steadily increasing their share of electricity generation, to the point where they constitute the majority of new installations in many countries. Again, the costs have been trivially small: in Australia’s case, made up almost entirely of the reduction in asset value imposed on existing generators.

There is as far as I am aware, no credible analysis to support the opposite claim (call it the economic armageddon hypothesis) that decarbonization will involve economic costs sufficient to greatly reduce living standards, or, for poor countries, prevent catchup to the developed world. (Again, more detailed argument over the fold.

Nevertheless, past experience suggests that lots of people are sufficiently wedded to the economic armageddon hypothesis that neither this, nor any other evidence will change their minds. I have previously analyzed this unwillingness to respond to evidence in terms of Noah Smith’s Bayesian definition of “derp“: “the constant, repetitive reiteration of strong priors”.

But I no longer think this is sufficient. A central concept of Bayesian decision theory is the separation of preferences from beliefs. That is, your subjective belief about the probability that a proposition is true should be independent of whether (because you have bet on it, or for some other reason) you want it to be true. This is the opposite of what is often called “motivated reasoning” or, less politely, “wishful thinking”.

This, I think, is the central distinction between “derp” and “denial”. Both involve the rejection of factual evidence that would (to a person without strong preconceptions) be overwhelmingly strong. This must involve strong prior beliefs. Denial differs from derp in that these factual beliefs derive from preferences, and are unlikely to undergo any updating. If anything, denial may be strengthened by evidence of the proposition being denied.

This in turn suggests different possible cures. Derp may eventually, if very slowly, be overcome by an accumulation of evidence. By contrast, denial can only be addressed by changing the source of wishful thinking; for example, by convincing rightwingers to stop being rightwingers.

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Third time lucky ?

So, it seems, we are signed up for our third Iraq war in 20-odd years. Obviously, this isn’t because the last two turned out brilliantly. So, what is the reasoning here? More precisely, given that Australia’s policy is just to follow the US without question, what is the reasoning of the world leaders, most importantly Obama, who are pushing this war? There seem to be two main points here

* ISIS/ISIL are barbaric terrorists who behead hostages. That’s a good reason for trying to capture and try those responsible, and perhaps for trying to kill them if that’s not possible. But there’s nothing special about this particular group. There are plenty of barbaric terrorists out there. And one of our leading allies in the fight, Saudi Arabia, routinely beheads people for such crimes as apostasy and “sorcery”. None of this justifies a war that is going to cost tens of billions of dollars (Australia alone looks to be up for several billion, assuming a long war) and an unknowable, but potentially large, number of lives.

* ISIS/ISIL threaten to take over large non-Sunni areas of Iraq and undertake ethnic/religious cleansing. That threat looked like a significant a month or two ago. But some limited air support for Kurdish and Shia militias appears to have turned the tide. As far as I can tell, ISIS/ISIL are now confined to Sunni areas where they have a fair degree of popular support. Changing that will be a costly and bloody business.

I expect most readers here will agree with me, and don’t plan to argue about with those who haven’t learned from the past. But I would like a pointer to any serious analysis making the case for a new war.

This is the model ? (updated and corrected)

The QS World University Rankings have just come out, and, as you might expect the top places (11 of the to 20 and 17 of the top 50) are dominated by US universities. By contrast Australia has five universities in the top 50 (ANU, Melbourne, Sydney, UQ and UNSW) So, you might think, this is a pretty good argument for following the US model. You get a different story, however, if you look at undergraduate enrolments (conveniently listed in Wikipedia)

I calculate that the 15 US universities in the top 50 have a total undergraduate enrolment of 210 000 (that’s dominated by a few public universities: Michigan, UC Berkeley, UCLA and Wisconsin-Madison, as well as Cornell which is partly public). By contrast, the five Australian unis enrol 148 000.

Adjusted for population, Australian students are about ten times as likely as Americans to attend a top 50 university.

Of course, the figures should be adjusted for fee-paying international students, who constitute a much larger share of the Australian student population than in the US. On the other hand, international enrolments at the top US universities are also increasing. And since many of them haven’t increased enrolments since the 1950s, the number of places for domestic American students is actually declining.

Note: I previously used the 2013 rankings. I’ve updated to the 2014 list, which includes UNSW and two more US universities. The ratios don’t change significantly as a result.

Further note In comments, reader Aldonius points to more accurate enrolment stats than I got from Wikipedia

109K domestic undergrads; 135K total (80% domestic) for ANU, Melbourne, Sydney, UQ and UNSW
723K domestic undergrads; 926K total (78% domestic) For all Oz universities

Here’s my US list

MIT 4528
Harvard 7200
Stanford 6980
Yale 5414
Chicago 5134
CalTech 978
Princeton 5336
Columbia 8365
Cornell 13935
JHU 6023
Michigan 27979
Duke 6495
Berkeley 25951
Northwestern 8459
UCLA 28674
NYU 19401
Wisconsin 29504
Total 210356

And for Australia

ANU 10231
Melbourne 38000
Sydney 32393
UQ 34228
UNSW 33000
Total 147852

Monochrome swans

I have a request[^1] for help from scientifically literate readers. A lot of my research work is focused on the problem of unforeseen contingencies, popularly, if ethnocentrically, described as “black swans”. In particular, I’m interested in the question of how you can prepare for such contingencies given that, by definition, you can’t foresee exactly what they will be. One example, with which I’m very pleased, is that of the precautionary principle. It seems reasonable to say that we can distinguish well-understood choices involving hazards from those that are poorly understood, and avoid the latter, precisely because the loss from hazard cannot be bounded in advance.

Anyway, I was thinking about this in relation to the actual case of black swans (or, from my own perspective, white swans). The question is: what principles would help you to avoid making, and acting on, the assumption “all swans are white (or, in my own case, black)”. It seems to me that the crucial fact here is that the shift from black to white, or vice versa, is, in evolutionary terms, a small one. So, if you used something like cladistics, you would avoid choosing feather color as a defining feature of swans, and birds in general. As I understand it, a phylogenetic approach starts with features that are very strongly conserved (body plans) and proceeds from there. But, rather than assume that my own understanding is correct, it seemed simpler to ask.

[^1]: There’s a blog-specific word for this, but I refuse to use it

Go8: The empire strikes back

Michael Gallagher of the Go8 has put out a press release in reaction to my piece in The Conversation on higher education reform, accusing me of “an attack on a straw man”. It’s a fine example of John Holbo’s two-step of terrific triviality. Gallagher backs away from his previous advocacy of deregulation as a positive benefit to the much weaker position I mentioned in the article that it is “unpalatable but necessary response to cuts in funding”, or, in Gallagher’s words that “the status quo is not an option”.
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