Dagon made a point about the social importance of guarantees. If a promise is broken, you know you have been cheated. If you are persuaded that there is only a 10% chance of losing your investment and you are unlucky, what do you know?

I doubt that we can over come our biases by focusing on what they are bad for and how they hurt us. We also need to think about what they are good for and why we have them.

Rather that estimating a probability, it would have been more interesting to ask "What emotional need are you trying to meet with this?"

If Mr Still-a-chance yearns for "souls go to heaven and meet God" why does he care about evolution? Isn't the soul the magic, special sauce that converts an ordinary animal body into a human? How does denying evolution help him?

Meanwhile, 20000000 years in the future, a multi-generation interstellar space ship has set up a colony on a distant planet with existing biology. The colony collapses but man does not go extinct, and 100000 years later they have re-established a civilisation of sorts.

They find that man is not an animal. His biology is entirely distinct. Which goes well with their myths of a double fall, from the sky to the ground and from the golden age to barbarism, but what really do they gain when they find that they do not have genealogical ties to the animals around them. Why is our far future Mr Still-a-chance the 2nd so pleased?

I find myself unable to imagine how Mr Still-a-chance would have answered, which piques my curiosity

Perhaps this post needs to be rehosted at http://www.sufferingfrombias.com for it gives no suggestion or hypothesis about overcoming bias. Here are three.

ONE: Friendships with people from different cultures helps one to realise that stuff one was brought up to accept sounds deeply weird to those who first encounter it as adults.

TWO: There are tells: little warning glitches. The trouble is that from the inside the tell doesn't make sense, but human memory depends on embedding items in networks of meaning, so the tells will not embed and get forgotten. An example from my personal life is reading about the recent shooting spree in Finland that left eight dead. On comment on this was that it was a big shock because the standard Finish murder involves a man going on a fishing trip with his best friend, knifing him during a drunken row, and, overcome by remorse, turning himself in.

I found the standard Finish murder incomprehensible. I could never imagine doing anything like that. Recently I've come to realise that I'm the odd one out. Perhaps I have an attachment disorder. I'm terrified of rows with friends because I see relationships as fragile, easily destroyed by a petty quarrel, and the breaking of affectional bonds as unbearably painful. (Notice that my beliefs are internally inconsistant: if breaking affectional bonds is as painful as I fear, my friends are clearly not going to inflict that pain on themselves by dropping me over a petty quarrel. Whoops!)

Here is the general interest bit: rows within marriages, love affairs, and close friendships, are a well known phenomenon (is this the understatement of the month?). So I've spent 30 years noticing this and forgetting it without realising the implications, noticing and forgetting, noticing and forgetting, over and over, without ever holding it in my awareness for long enough to say "Hey! Wait a minute..."

Suggestion two is to keep a little black book of the stuff that keeps getting dropped on the floor. So it one was brought up a Christian one might notice when a daughter or fiancee unexpectly falls pregnant this never raised hopes of a second coming or a new relevation. After a while one realises that one never follows this thought anywhere, even though there is something odd about it. Into the black book it goes.

Later you can look through the book and start trying to worry out what is so slippery about the thought. Write down the stuff that doesn't make sense so that it has a chance against the much more easy to remember stuff that fits into your world view.

THREE: Fine distinctions of sarcasm. When one of one's favorite views is attacked by a sarcastic comment it sometimes irritates and it sometimes stings.

Sometimes the humour depends on an oversimplification. Perhaps the humour priviledges the ex post perspective over the ex ante perspecitive. This irritates because the attack is short and funny and the repost is long and dull, and yet ex post is not inherently better than ex ante, the argument is being decided by structural matters independent of the merits of the case.

Othertimes the humour lies in the fact that the sarcasm cuts through the bullshit and the defense mechanisms and pierces to the heart of the matter. This stings. The only defence is to remember all the worthless sarcasm that depends on distortion and irritates rather than stings and to pretend that this sting is also an irritation.

There is an interesting bias in the way that we approach these issues. We see ourselves as the prisoners of the system not the jailors. Or maybe I should say that we don't like to admit that we are lords as well as serfs.

One political response to the problem of lost purposes is to focus on government coercion which leads to libertarianism. I don't think that we should rush so quickly to a conclusion. First we should examine the origins of the problem more closely.

The key concept is contestability: is there an alternative BA course you can take that does not require mastery of 12 century knitting patterns. This not lead automatically to free-marketry. One can image contestible socialism.

Think about driving licences. Why does there have to be a single agency that issues them. The government could fund two, splitting the money in proportion to the number of licences issued. If queues are too long at one office, drivers will go to the over. It gets rather interesting if the competing offices get to set different driving tests. Do you go for the easy one or the hard one. Perhaps drivers who have passed the hard one get cheaper insurance rates. Perhaps that also tells you something important about the extra preparation being personally worth while, not just a money saving measure.

My favourite example is prison regimes. What do we expect from prison? We could set up a Prison Audit Agency that follows up prisoners 5 years after release to see how they are earning their money. There are many possibilities: professional criminal, dead, junkie, wino, deadbeat, honest employee, honest sole-trader, honest employer.

Imagine that the rehabilitation figures got the same kind of political attention as the crime figures. It would open the door to randomised assignment to different regimes. The hangers and floggers could run one prison, the hugs and therapy crowd another.

My guess is that neither really knows much about rehabilitation, a point that would become very clear a decade on as the figures are disappointing for both regimes. Both groups would be humbled and forced to think harder about what they were doing least their rivals responded more wisely and eventually built up a commanding lead in the results.

School vouchers are another example. Most state supported school systems are designed as pay-twice systems. If you pull your child out, you continue to pay taxes as before, but do not get the money back. You must find a second tranche of funds to pay your child's school fees. So schooling is only weakly constestible.

The curious point is that state power is weakly contestible, leading to poor delivery of services to the voter, who wearies of his political leaders and votes them out of office. Why do politicians favour a system that costs them office?

As we follow politics we see that reforms that make public services contestible, even when they remain in the state sector, are bitterly contested by civil servants. And not just public services. Trade barriers are about stopping the consumer from buying Toyota instead of General Motors, because the auto workers don't want their claim to be building wonderful cars to be contestible.

The 90% of us who are above average will do anything to keep the sunshine of contestibility from illuminating our particular patch line of work and causing our illusion to crumble to dust.

I don't see any hope for a direct attack on our tendency to lose our purposes. We like it that way and will fight to keep it like that. More insidiously we will always see ourselves as serfs not lords. Is there a name for this bias, the one that stops us admitting to ourselves that we are doing it to ourselves?

X3J13, the ANSI committee that standarised Common Lisp, had many problems to solve. Kent Pitman credits Larry Masinter with imposing the disciple of seperating problem descriptions from proposed solutions and gives insights into what that meant in practise in a post to comp.lang.lisp

http://tinyurl.com/2hppgs

The general interest lies in that fact that the X3J13 Issues were all written up and are available on line.

http://www.lispworks.com/documentation/HyperSpec/Front/X3J13Iss.htm

or

http://www.lisp.org/HyperSpec/FrontMatter/X3J13-Issues.html

so if you wish to study how this works there is a resource you can analyse.

I should confess that my interest has been in content not process. I have been reading these issues to learn Common Lisp. Are these pages really a useful resource for scholars wishing to study the separation of problem descriptions from proposed solutions? I don't know.

Tom, I think we are actually agreeing. I'm arguing that if you already know the situation is complicated you cannot just appeal to Occam's Razor, you need some reason specific to the situation about why the simple hypothesis should win.

You are proposing a reason, specific to economics, about why the complications might be washed away, making it reasonable to prefer the simpler hypothesis. My claim is that those extra reasons are essential. Occam's Razor, on its own, is useless in situations known to be complicated.

Do high level descriptions of the world frequently account for most of the variance in high level phenomena without containing the known complexity of the substrate?

I think you can constrast thermodynamics and sociology by noticing that there is no Princess Diana molecule. All the molecules are on the same footing. None of them get to spoil the statistics by setting a trend and getting in all the newspapers papers. So perhaps Occam's Razor grabs credit not due to it, as researchers favour simple theories when they have specific reasons to do so.

An example of the mis-use of Occam's Razor arises in discussion of the question of whether minimum wage laws cause unemployment. Many people think they do and it is reasonable to imagine a politician finding an increase in the minimum wage to be politically necessary even as he wonders how to dodge blame for the subsequent rise in unemployment that he believes will follow. He will likely look to timing, seeking to delay the increase until there is a good chance of a tightening labour market raising wages.

How can you do empirical research on the effect of minimum wage laws on employment when practical men are scheming to conceal the very effect that you are looking for? One way is to appeal to Occam's Razor. Let us prefer the simpler hypothesis that increases to the minimum wage are random. That is bogus. We already know of the politicing and scheming that goes on. If our research methods cannot accommodate it, they leave us in the dark and Occam's Razor does not light our way.

Occam's Razor has two aspects. One is model fitting. If the model with more free parameters fits better that could merely be because it has more free parameters. It would take a thorough Bayesian analysis to work out if it was really better. A model that fits just as well but with fewer parameters is obviously better.

Occam's Razor goes blunt when you already know that the situation is complicated and messy. In neurology, in sociology, in economics, you can observe the underlying mechanisms. It is obvious enough that there are not going to be simple laws. If two models fit equally well, you just don't know, even if one is simpler than the other.

The "quant" trying to make money on the financial markets can take a modelling approach and may find the Razor sharp, but the scientist, trying to get to the bottom of things, has little reason to go for an explanation simpler than the known complexity of the underlying mechanisms.

The Vapnik Chernovenkis Dimension also offers a way of filling in the detail of the the concept of "simple" appropriate to Occam's Razor. I've read about it in the context of statistical learning theory, specifically "probably approximately correct learning".

Having successfully tuned the parameters of your model to fit the data, how likely is it to fit new data, that is, how well does it generalise. The VC dimension comes with formulae that tell you. I've not been able to follow the field, but I suspect that VC dimension leads to worst case estimates whose usefulness is harmed by their pessimism.

Tiiba, I've always considered this bible quote

"I returned and saw under the sun, that the race is not to the swift, nor the battle to the strong, neither yet bread to the wise, nor yet riches to men of understanding, nor yet favour to men of skill; but time and chance happeneth to them all."

to be a paradigm of bad writing. The nasty trick it exemplifies is using a paradox to get one up on the reader without committing to a specific meaning.

If the race is not to the swift, who does win? The lucky? Contrast two aphorisms "the race is to the swift" and "the race is to the lucky". The second of these is useless. You cannot assess some-one's luck ahead of time, you have to discover who is lucky by waiting to see who wins and then say smugly "see I told you the lucky one would win."

This passage irritates me because the writer forces the reader to create the meaning of the passage from nothing and then the writer appropriates the readers efforts. There is something important to be said on this theme:

The race is to the swift and the battle to the strong, but the odds are never quite so short as the book maker offers and the greatest number are drowned when the sea takes the unshinkable ship with no lifeboats.

I've no doubt that the author of Ecclesiastes would say "that's it, you have got my meaning exactly" but that would be a lie; it is my meaning, I said it and he didn't.