Overcoming Bias

The Failures of Eld Science

Followup to:  Initiation Ceremony, If Many-Worlds Had Come First

This time there were no robes, no hoods, no masks.  Students were expected to become friends, and allies.  And everyone knew why you were in the classroom.  It would have been pointless to pretend you weren't in the Conspiracy.

Their sensei was Jeffreyssai, who might have been the best of his era, in his era.  His students were either the most promising learners, or those whom the beisutsukai saw political advantage in molding.

Brennan fell into the latter category, and knew it.  Nor had he hesitated to use his Mistress's name to open doors.  You used every avenue available to you, in seeking knowledge; that was respected here.

"- for over thirty years," Jeffreyssai said.  "Not one of them saw it; not Einstein, not Schrödinger, not even von Neumann."  He turned away from his sketcher, and toward the classroom.  "I pose to you to the question:  How did they fail?"

The students exchanged quick glances, a calculus of mutual risk between the wary and the merely baffled.  Jeffreyssai was known to play games.

Condemned to Repeat Finance Past

Those who cannot remember the past, are condemned to repeat it. Santayana

I once said:

I'd guess you can get 80% of the improvement that predict markets offer by using a much simpler solution: collect track records.

Case in point - stock investors:

Based on the answers of 215 online broker investors to an Internet questionnaire, we analyze whether investors are able to correctly estimate their own realized stock portfolio performance. We show that investors are hardly able to give a correct estimate of their own past realized stock portfolio performance and that experienced investors are better able to do so.

It is hard to learn from experience if you don't remember what you did and how well that worked. 

Many Worlds, One Best Guess

Previously in series: Collapse Postulates
Followup to:  Bell's Theorem, Spooky Action at a Distance, Quantum Non-Realism, Decoherence is Simple, Falsifiable and Testable

If you look at many microscopic physical phenomena - a photon, an electron, a hydrogen atom, a laser - and a million other known experimental setups - it is possible to come up with simple laws that seem to govern all small things (so long as you don't ask about gravity).  These laws govern the evolution of a highly abstract and mathematical object that I've been calling the "amplitude distribution", but which is more widely referred to as the "wavefunction".

Now there are gruesome questions about the proper generalization that covers all these tiny cases.  Call an object 'grue' if it appears green before January 1, 2020 and appears blue thereafter.  If all emeralds examined so far have appeared green, is the proper generalization, "Emeralds are green" or "Emeralds are grue"?

The answer is that the proper generalization is "Emeralds are green".  I'm not going to go into the arguments at the moment.  It is not the subject of this post, and the obvious answer in this case happens to be correct.  The true Way is not stupid: however clever you may be with your logic, it should finally arrive at the right answer rather than a wrong one.

In a similar sense, the simplest generalizations that would cover observed microscopic phenomena alone, take the form of "All electrons have spin 1/2" and not "All electrons have spin 1/2 before January 1, 2020" or "All electrons have spin 1/2 unless they are part of an entangled system that weighs more than 1 gram."

Happy Conservatives

At Freakonomics, Arthur Brooks on why conservatives seem happier:

In my last post I showed the large happiness differences between religious Americans and secularists, and argued that this is a big part of the reason conservatives are so much happier than liberals. But I also noted that religion and other lifestyle distinctions still only explain about half the gap. ...

In my book I argue that conservatives are more optimistic about the future than liberals are, and believe in each individual's ability to get ahead on the basis of achievement. Liberals are more likely to see themselves and others as victims of circumstance and oppression, and doubt whether individuals can climb without governmental help.

I wonder:

• Would you or I be happier if we let ourselves think more conservatively, such as by attending church more and believing we can pull ourselves up by our bootstraps?
• Would society be happier if we encouraged more conservative thoughts?
• If so, who wants such outcomes?  (Or, are they good outcomes?)

Me, I want to believe whatever is true even if that makes me unhappy.  And with that attitude, I doubt attending church would make me happier.   

If Many-Worlds Had Come First

Followup to: Collapse Postulates, Decoherence is Simple, Falsifiable and Testable

Not that I'm claiming I could have done better, if I'd been born into that time, instead of this one...

Macroscopic decoherence - the idea that the known quantum laws that govern microscopic events, might simply govern at all levels without alteration - also known as "many-worlds" - was first proposed in a 1957 paper by Hugh Everett III.  The paper was ignored.  John Wheeler told Everett to see Niels Bohr.  Bohr didn't take him seriously.

Crushed, Everett left academic physics, invented the general use of Lagrange multipliers in optimization problems, and became a multimillionaire.

It wasn't until 1970, when Bryce DeWitt (who coined the term "many-worlds") wrote an article for Physics Today, that the general field was first informed of Everett's ideas.  Macroscopic decoherence has been gaining advocates ever since, and may now be the majority viewpoint (or not).

But suppose that decoherence and macroscopic decoherence had been realized immediately following the discovery of entanglement, in the 1920s.  And suppose that no one had proposed collapse theories until 1957.  Would decoherence now be steadily declining in popularity, while collapse theories were slowly gaining steam?

Imagine an alternate Earth, where the very first physicist to discover entanglement and superposition, said, "Holy flaming monkeys, there's a zillion other Earths out there!"

In the years since, many hypotheses have been proposed to explain the mysterious Born probabilities.  But no one has yet suggested a collapse postulate.  That possibility simply has not occurred to anyone.

One day, Huve Erett walks into the office of Biels Nohr...

Elusive Placebos

Alas, I have treated the Placebo effect too uncritically in my health econ class.  I'll do better next year.  From Wikipedia:

The original 1955 article of Beecher "The Powerful Placebo" claimed a 35% placebo effect in 15 studies. The original article was in 1997 re-analysed and "no evidence was found of any placebo effect in any of the studies" used by Beecher. ... The claimed "effects" were produced by spontaneous improvement, fluctuation of symptoms, regression to the mean, additional treatment, conditional switching of placebo treatment, scaling bias, irrelevant response variables, answers of politeness, experimental subordination, conditioned answers, neurotic or psychotic misjudgment, psychosomatic phenomena, misquotation, etc. ...

Hróbjartsson and Gøtzsche published a study in 2001 and a follow-up study in 2004 questioning the nature of the placebo effect. ... They performed two meta-analyses involving 156 clinical trials in which an experimental drug or treatment protocol was compared to a placebo group and an untreated group, and ... found that in studies with a binary outcome, meaning patients were classified as improved or not improved, the placebo group had no statistically significant improvement over the no-treatment group. Similarly, there was no significant placebo effect in studies in which objective outcomes (such as blood pressure) were measured by an independent observer. The placebo effect could only be documented in studies in which the outcomes (improvement or failure to improve) were reported by the subjects themselves.

HT to Brandon Reinhart.

Collapse Postulates

Previously in series:  Spooky Action at a Distance
Followup to:  Decoherence is Simple, Falsifiable and Testable

Back when people didn't know about macroscopic decoherence aka many-worlds - before it occurred to anyone that the laws deduced with such precision for microscopic physics, might apply universally at all levels - what did people think was going on?

The initial reasoning seems to have gone something like:

"When my calculations showed an amplitude of -1/3i for this photon to get absorbed, my experimental statistics showed that the photon was absorbed around 107 times out of 1000, which is a good fit to 1/9, the square of the modulus."

to

"The amplitude is the probability (by way of the squared modulus)."

to

"Once you measure something and know it didn't happen, its probability goes to zero."

Read literally, this implies that knowledge itself - or even conscious awareness - causes the collapse.  Which was in fact the form of the theory put forth by Werner Heisenberg!

Faith in Docs

Today is my health econ final exam.  I also return their last paper, on faith healing.  After an entire semester hearing how we get little health value from a wide margin of medical spending, almost every student (21 undergrads & 9 grads) said that a big argument against legal faith healing is that it can discourage people from going to regular doctors.  Most also said it is hard to evaluate faith healer quality, and to know if they are just in it for the money.   

Sigh.  Regular docs are mostly in it for the money, and are also hard to evaluate.  If we on average get near zero health from our last units of medicine, we are better off replacing those units with anything cheaper, at least if it also gives near zero net health effect and similar non-health benefits.  Faith healing seems to fit this bill. 

Sure, we vary in how much medicine we get, and in how much we would substitute legal faith healing for medicine.  So yes a general trend toward more faith healing would no doubt produce a few people who sometimes get too little medicine.  But that harm should be far outweighed by a reduction in harmful overtreatment.  Alas, apparently even econ students after a semester of my indoctrination can't see this (only two mentioned it) - we all just love docs too much. 

I'm struck by how emotional was the opposition to faith healing and how timid were its supporters.  Most people believe prayer can make you well, but few believe religious specialists can use such powers to similarly help others.  Yet our faith in docs is so strong that when considering medical quantity variation, a few getting too little dominates our attention - we just can't see most getting too much.

Quantum Non-Realism

Followup to:  Bell's Theorem

"Does the moon exist when no one is looking at it?"
        -- Albert Einstein, asked of Niels Bohr

Suppose you were just starting to work out a theory of quantum mechanics.

You begin to encounter experiments that deliver different results depending on how closely you observe them.  You dig underneath the reality you know, and find an extremely precise mathematical description that only gives you the relative frequency of outcomes; worse, it's made of complex numbers.  Things behave like particles on Monday and waves on Tuesday.

The correct answer is not available to you as a hypothesis, because it will not be invented for another thirty years.

In a mess like that, what's the best you could do?

Expelled Beats Sicko

Metacritic (a review aggregator) gives Michael Moore's latest movie Sicko a 74 out of 100, while the new Expelled gets only a 20.  Expelled, however, is a better movie.

In Sicko, Moore shows US folks facing high prices for docs, drugs, and surgery.  Sad anxious people find that if they can't pay, they may not be treated.  But then we see happy glad folks in England, France, and Canada getting all the medicine they want for free.  Free good, expensive bad -- that is the depth of Moore's celebrated case for universal care.

Sicko makes Expelled seem like a graduate seminar.  In Expelled, experts on many sides speak at length in their own words.  The movie makes a good case for its main claim, that intelligent design advocates are shunned by academia.  And they get opponent Richard Dawkins to admit a 1% chance of God, and a higher chance Earth life may have been designed by distant ancient higher powers.  Both these estimates justify devoting higher-than-now fractions of origin-of-life research to such possibilities.  (And I estimate betting markets would endorse >1% chances for these.)

For my taste, the movie overdid threats to a mythical "academic freedom" that supposedly made the US great, but probably never existed.  It also overdid how understanding Darwin leads people to reject God, and emboldened Nazis to brutality.  These claims are not relevant to the truth of intelligent design, but they are admittedly true and relevant to most viewers' desire to avoid beliefs with such consequences. 

Sadly, it seems reviewers praised Sicko because they agreed with universal care, and panned Expelled because they disagreed with intelligent design.  The tug-o-war continues.

Should-be-unneeded disclaimers: There are good arguments possible for universal care, and in a betting market I'd probably be short both God and universal design.