31 May 2014

Rational skepticism

I decided to start writing again.

I have recently become a member of the stock owning class.

With the birth of my daughter I decided to save for her future university education. While there is always the chance I will become Prime Minister and she will be offered a secret $60,000 scholarship, I think its better to hedge her bets by starting a university fund.

Now the pot has grown large enough, I've invested it in stocks.

The amount is tiny, the risk minuscule and my level of research in the relevant companies infinitesimal  – naturally I watch them like a hawk, becoming enraged when my holdings in Wesfarmers fall by 76 cents and euphoric when Woolworths investment grows by $1.20.

I've deepened my involvement in this penny ante game by reading blogs, website and columnists who all claim searing insights into the futures of listed companies they have never worked for run by managers and directors they have never spoken to.

Turns out their predictive ability is no better than mine despite the no doubt countless hours spent pouring over information.

So my issue is this: what is the rational level of skepticism in “expert opinion”?

Obviously throwing out all expert views and trusting to blind faith is foolish. I still hold sacred the right to treat with derision and contempt vaccine skeptics, holocaust revisionists and climate change deniers.

So where is the line?

Perhaps we can start with the proposition that skepticism of established data puts you on shaky ground. So we can be skeptical whether a new “pandemic” will kill all human life on the planet (though hopefully it will still get Gwyneth Paltrow), but only an idiot would argue that vaccines cause autism.

Next rule, its dangerous to trust the opinion of a person whose salary depends on them holding that opinion. So when my local bishop told me in school that the Catholic church would never cover for a Marist brother involved in child abuse, I should really have been a little less trusting.

Third rule, predicting based on an ideological stand point should be done with care.  It exposes you to the risk of confirmation bias. 

Last rule, real world systems are complex. Lots of things both visible and hidden can skew predictions. Hard simple rules don't usually have great predictive ability beyond the obvious.

With this in mind, I vow to be less firm in my future predictions on this blog and more open to opposing arguments in my every day life.

I also intend to keep my stock buys to safe blue chips.

I'm also going to try to write at least once a fortnight, whether anyone reads it or not.

As always, your comments are appreciated...even the trolling.


  1. note to self, read this blog more, even if it's just to increase the traffic...

    1. Good reasoning...Damn good reasoning

  2. Happiness is an opportunity for ranting! Being pro ranting, I've added you to my blog list.


    1. I'm pleased to satisfy a niche market