Notes on “Predictably Irrational” by Dan Ariely
I just finished reading the new book Predictably Irrational, which was recommended to me by Andreas Weigend. It looks like it will be a big hit for this year.
The book is a fun read, mostly Dan experiments on MIT students and shows how people make decisions that are different from what standard economic theory assumes. The experiments are interesting and seem well designed — the main problem I have with the book is that Dan takes these tightly controlled, very focused results and suggests that they are generalizable enough for him to recommend sweeping policy changes that would fix our healthcare system, consumer debt and teen pregnancy. After a while I took to reading the experiments and skipping over his rather broad interpretations of what they mean.
Anyway, I read a lot of this sort of soft-non-fiction and usually end up forgetting all the experiments described, so I’ve taken to making notes. The ways in which people behave irrationally may be useful reference material for me in the future
I thought I’d share my completely unedited notes here:
- People choose things on the basis of comparisons. Given multiple choices they will gravitate towards those where an easy comparison is available. Companies exploit this by offering several options of a heretofore unseen product so people can see what a good deal the cheaper option is.
- People are anchored to prices, usually the first price they encounter for a specific item. This holds true even when the first price they encounter is negative meaning that something can be perceived as a punishment or a reward depending on how it was framed initially.
- People strongly overweight the value of items that are free because of loss-aversion, making them forgo options that are a fantastic deal if a free alternative is available
- Introducing payment for a service shifts people from social norms to market norms. People are much more likely to do something for free than they are to do it for a payment that they regard as too low. Gifts are social norms and do not count as money unless the price is explicitly stated.
- Even thinking about money where non is involved can shift people from social to market norms. Further, once market norms are established it’s very difficult to get rid of them.
- Sexual arousal changes people’s tolerance of what they deem acceptable, to a degree that they were not able to predict beforehand
- Students given periodic deadlines will perform better than those with no deadlines. Given the chance, most students will set their own evenly-spaced deadlines and perform well.
- People value things that they already have much more highly. Duke students were willing to pay only $170 for a ticket that a holder would sell for no less than $2400, even though tickets were distributed randomly (combination of loss-aversion and endowment effect)
- Bidders in auctions become attached to items, proportional to the amount of time that they believed they were winning
- Most people will attempt to keep their options open, even at the expense of choosing the best option. Often a better strategy would be to close off bad options entirely. The consequences of delaying commitment are often worse than than making the wrong choice.
- Coffee tastes better when the condiment containers are expensive
- Given a blind choice between beer and beer laced with Balsamic, more people chose the tainted beer. When they were told ahead of time that the second beer was tainted, they acted disgusted when they tried it
- Generally, expectation of an experience strongly affects actual feelings about an experience. Learning about the vinegar after tasting the beer did not prevent people from saying they liked it.
- Most people are inclined to be honest about big things even if they won’t get caught but are happy to cheat on small things even if there’s a chance they will get caught
- Ostensibly honest people are less likely to steal cash directly than they are to steal the equivalent amount in goods
March 15th, 2008 at 6:42 pm
[…] Note: Often, users are irrational. […]
March 17th, 2008 at 11:21 am
hi,
my name is yoram, i am dan’s father.
i read with great interest your reviewe.
may i ask you add a short review to the amazon reviews?
thanks a lot,
yoram.
March 18th, 2008 at 7:57 pm
What are the implications - that we can be manipulated in new ways to buy things we don’t need or pay more for them than we should?
March 20th, 2008 at 1:07 am
[…] kiwitobes.com » Blog Archive » Notes on “Predictably Irrational” by Dan Ariely (tags: cognition economics brain interesting psychology) […]
April 4th, 2008 at 1:34 pm
None…
None…
April 11th, 2008 at 2:18 am
Huh… Slightly addled, but on the whole I like this post. You’ve got some fresh ideas. But please, write more lucid.
May 1st, 2008 at 7:52 pm
Huh… Slightly addled, but on the whole I like this post. You’ve got some fresh ideas. But please, write more lucid.
May 1st, 2008 at 7:53 pm
thanks
May 2nd, 2008 at 6:56 am
Well, your notes are interesting, I am considering buying the book to have a look:)
July 15th, 2008 at 2:57 pm
thank you very good
September 3rd, 2008 at 1:56 pm
For book details, write to me at;
testndtv3@yahoo.com
November 9th, 2008 at 9:02 am
Hi webmaster!
May 7th, 2009 at 10:11 am
thanks
August 30th, 2009 at 4:14 pm
How long have you been blogging…your good at it.
November 23rd, 2009 at 9:09 am
technologies that have created a paradigm shift in the software industry – I was born just after the spinning magnetic hard drive was created. Off the top of my head I can think of: the Internet (thanks Al!), optical disks, Windows, and parallel computing. From each of these technologies entirely new software