Overcoming Bias

Dinos on the Moon

At the SETI conference last week I was surprised to hear NASA's Chris McKay suggest we look for dinosaur relics on the moon.  Dinos went suddenly extinct about 65M years ago, and the dino fossil record seems spotty enough that we could have missed a lineage that went from possum to human sized brains in the ~10M year period it took mammals.  We could also have missed relics of a stone-tool phase that lasted only .2M years.  But a dino lander left on the moon should stay visible a very long time. 

Humans have apparently already dug up a substantial fraction of the richest near-surface Earth metal deposits.  So a dino civilization that went much beyond our metal usage would have left a signature in reduced rich metal deposits.  And since the metal doesn't actually disappear, they would also have left "strange" metal-junkyard deposits.  If modest efforts by geologists could exclude this possibility, that seems well worth the effort. 

It would be very big and bad news to hear that metal-using dinos suddenly went extinct just when the other dinos did, and immediately after becoming big metal users.  If so, either dinos destroyed themselves with far more power than we humans can now muster, or powerful aliens exterminated them.

From McKay's 1996 paper "Time for intelligence on other planets":

Nanotech Views Value Driven

In another experiment conducted with the Washington-based Project on Emerging Nanotechnologies at the Woodrow Wilson International Center for Scholars, Kahan found that when volunteers heard about the risks of nanotechnology from different experts, they gravitated toward the views of experts who seemed to share their personal values -- individualists followed the lead of experts who appeared to be individualists, while people who believed in hierarchy were most likely to be influenced by experts who espoused similar views. Once volunteers decided which experts were most like them, it did not make a difference whether the experts said nanotechnology was risky or safe -- either way, the volunteers agreed with them. ... When people clash on hot-button issues, their disagreements may have more to do with clashing values than facts. One person may conclude nanotechnology is dangerous while another person concludes it is safe, but neither realizes their conclusions are being driven by underlying values that have nothing to do with nanotechnology.

That is from the Post.  Of course regarding policy conclusions, all else equal it does make sense to listen more to people who share your values.   But it seems a shame if your views about facts contain nothing more. 

For Discount Rates

(A long retort to Eliezer's post Against Discount Rates.)

Imagine you are a multi-billionaire who, to benefit mankind, will construct an asteroid deflector.  Since your budget is limited, the deflector cannot be perfect. And trying to deflect an asteroid heading toward one place may mean increasing the risk it will hit somewhere else.  So you must decide how much protection to offer different parts of the globe.  Let us assume that your protection can be described by a single parameter P at each place X -- roughly how much you have reduced the probability that an impact there will cause a physical effect (e.g. temperature) there above a certain threshold. 

Initially you decide that it would be biased to prefer some places X on Earth to others, and so you decide to give the same protection level P(X) = P to all places.  To make clear to everyone the magnitude of your generosity, you publish a cost schedule C(X) saying how many dollars per square mile it will cost you, per unit of protection, to increase (or decrease) protection at each place.  It might, for example, cost more to protect places near the equator, and less to protect places toward the poles.

Soon you find that rich densely-populated places X toward the poles are offering to pay you a price above C(X) to increase their protection P(X).  Accepting their offers benefits them, and gives you more money to spend on benefiting everyone, so you accept.

Econ of Longer Lives

I'm a little late to the party, but in December's Cato Unbound debate, Aubrey de Grey and Ronald Bailey argued that much longer healthy lifespans would be good, while Diana Schaub and Daniel Callahan had doubts.  Some samples:

Daniel Callahan: My standing complaint against de Grey and his enthusiastic colleagues is that they defend themselves by hypothesizing a variety of changes in our present way of life that would make our extended lives a kind of heaven on earth. We would be so healthy and energetic we would want to keep working indefinitely. We could start new careers, new families, new ways of life. That we might get tired of it all, or bored, is not allowed into their calculations. Nor is any imaginative effort to imagine the deleterious social effects allowed.

Ronald Bailey: So what about the social consequences of radically longer and healthier lives? In that regard, Diana Schaub in her reaction essay raises many questions for reflection about those consequences, but curiously she fails to actually reflect on them.  Schaub ... simply recapitulates the standard issue pro-mortalist rhetorical technique of asking allegedly "unnerving questions" and then allowing them to "fester in the mind." Sadly, all too many bioethicists think they've done real philosophic work by posing "hard" questions, then sitting back with steepled hands and a grave look on their countenances.

This issue has sparked many debates, conferences etc. over the last few years.  The invited participants have naturally been intellectuals who have published on the topic recently, mainly activists and bioethicists.  We economists have not published on this topic, and so have not been included.  But this is not because we have nothing to say.  Instead, no economist has anything special to say.  We can all easily see that standard economic theory seems to say longer healthy lives are a good thing.  So none of us thinks any of us should get precious academic publication credit for saying such an obvious thing.  As a result, life extension debates ignore economic theory. 

Of course appearances may be deceiving, so perhaps there are good economic theory reasons against longer healthy lives.  And perhaps economists would typically let their "judgment" overrule economic theory on this issue.  But it still seems to me a shame that observers of this debate can remain unaware of what standard economic theory seems to say on this subject. 

When None Dare Urge Restraint

Followup to:  Uncritical Supercriticality

One morning, I got out of bed, turned on my computer, and my Netscape email client automatically downloaded that day's news pane.  On that particular day, the news was that two hijacked planes had been flown into the World Trade Center.

These were my first three thoughts, in order:

I guess I really am living in the Future.
Thank goodness it wasn't nuclear.
    and then
The overreaction to this will be ten times worse than the original event.

Nature Endorses Human Extinction

In the latest Nature, Chris Thomas says:

This year the baiji river dolphin (Lipotes vexillifer), a victim of the pollution and boat traffic of China's Yangtze river, was added to the list of creatures on the verge of extinction. Is this part of the sixth mass extinction in 450 million years, or does the recent spate of losses caused by humans represent a blip in the history of life on Earth? Michael Novacek's Terra takes stock of the situation and provides an opportunity to learn from the past.  ... 

Of course, we shall solve some of these issues with technological fixes. Yet if we maintain 9 billion avaricious people on Earth for the next millennium, a sixth extinction event seems inevitable.  The geological perspective of Terra is bizarrely reassuring. Humans will presumably be gone within a few million years, perhaps sooner. If the past that Novacek describes is a guide to the future, global ecosystem processes will be restored some tens of thousands to a million years after our demise, and new forms of life over the ensuing millions of years will exploit the denuded planet we leave behind. Thirty million years on, things will be back to normal, albeit a very different `normal' from before. It is good to be optimistic. The problem is living here in the meantime.

Thomas is "optimistic" that humans and any descendants with a remotely similar population or resource-intensive technology will be extinct in a million years.   Yet if a plague, for example, were to produce this outcome within the next ten years, I'm pretty sure most everyone would see this as a catastrophe of the highest possible order.  So how does this become a good thing if it happens in the next million years?

Added 21Nov:  I emailed Chris Thomas the day of this post, and today he commented that I was "over-interpreting a few tongue-in-cheek comments."  I responded.

The Logical Fallacy of Generalization from Fictional Evidence

When I try to introduce the subject of advanced AI, what's the first thing I hear, more than half the time?

"Oh, you mean like the Terminator movies / the Matrix / Asimov's robots!"

And I reply, "Well, no, not exactly.  I try to avoid the logical fallacy of generalizing from fictional evidence."

Some people get it right away, and laugh.  Others defend their use of the example, disagreeing that it's a fallacy.  This issue comes up often, and I plan to refer people to this page; so the following post is a bit long...

Why More History Than Futurism?

Far more academics study the past than the future.  That is, while most academics may study unchanging truths which apply equally well to all times, among academics who focus on particular times other than our own, far more focus on past than future times.  Why?   

Yes, we have more data on the past, but the future seems more interesting.  Our decisions today have far more influence on aspects of the future we care about, than the past.  And academics often overlook less interesting topics with lots of data, to focus on harder but more interesting topics.

Since we are more uncertain about the future than the past, study of the future would consist in elaborating more scenarios in less detail, relative to fewer more-detailed past scenarios.  Futurists could be hitech, constructing vast computer simulations and decision trees.  As with history, futurists could scour other fields for clues about the time they study.  Surely some people would be better at these tasks than others, so future study could also serve to signal intellectual ability. 

So why more history than futurism?  My best guess is that non-futurism intellectuals find it harder to independently evaluate claims about the future, relative to the past.  Ordinary people can read historians and be impressed by their apparent command of detail and care of analysis.  Such readers can then similarly impress each other by quoting what historians tell them.  It would be far harder to do similar things for the future.  If true, this theory suggests amateur evaluation importantly influences academic attention.

I'm not very confident in this theory though; anyone have other explanations?  From a lunch conversation a week ago. 

Burdensome Details

Followup to:  Conjunction Fallacy

 "Merely corroborative detail, intended to give artistic verisimilitude to an otherwise bald and unconvincing narrative..."
            -- Pooh-Bah, in Gilbert and Sullivan's The Mikado

The conjunction fallacy is when humans rate the probability P(A&B) higher than the probability P(B), even though it is a theorem that P(A&B) <= P(B).  For example, in one experiment in 1981, 68% of the subjects ranked it more likely that "Reagan will provide federal support for unwed mothers and cut federal support to local governments" than that "Reagan will provide federal support for unwed mothers."

A long series of cleverly designed experiments, which weeded out alternative hypotheses and nailed down the standard interpretation, confirmed that conjunction fallacy occurs because we "substitute judgment of representativeness for judgment of probability".  By adding extra details, you can make an outcome seem more characteristic of the process that generates it.  You can make it sound more plausible that Reagan will support unwed mothers, by adding the claim that Reagan will also cut support to local governments.  The implausibility of one claim is compensated by the plausibility of the other; they "average out".

Which is to say:  Adding detail can make a scenario SOUND MORE PLAUSIBLE, even though the event necessarily BECOMES LESS PROBABLE.

If so, then, hypothetically speaking, we might find futurists spinning unconscionably plausible and detailed future histories, or find people swallowing huge packages of unsupported claims bundled with a few strong-sounding assertions at the center.

Your Future Has Detail

Our visions of future events don't include a lot of detail.  In the Sept. 7 Science, Gilbert and Wilson discuss the many resulting biases: 

We feel better when we imagine going to the theater than to the dentist, but we feel better imagining either event on a sunny day than on a rainy day, or when we are well rather than ill. ... When people who have missed trains in the past are asked to imagine missing a train in the future, they tend to remember their worst train-missing experience rather than their typical train-missing experience. ... which leads them to overestimate how painful the next train-missing experience will be.

Similarly, when people experience an unpleasant episode that ends in brief relief - for example, submerging their arms for 90 s in a bath of ice water that is slightly warmed in the final 30 s - they tend to remember the closing moments of the experience rather than the most typical moments ... which leads them to underestimate how painful the recurrence will be. It seems that everyone remembers their best day, their worst day, and their yesterday. Because unusual events and recent events are so memorable, people tend to use them when constructing simulations of future events. ... Because simulations omit inessential features, people tend to predict that good events will be better and bad events will be worse than they actually turn out to be ...