Prospect Theory and Health Decisions


If you’re a staff member at Dental on Flinders or a long-term patient, you may have heard me worship Daniel Kahneman and Amos Tversky over the years. Daniel Kahneman’s Thinking Fast and Slow is a must read for anyone that makes decisions for a living. This book has had an enormous influence on my practicing career as a dentist as well as my private life.

Kahneman, a psychologist, received the Nobel Prize for his work in behavioural economics in 2002. His seminal work is prospect theory. The following is from prospect theory:

When faced with a sure win: Most people will take the win without gambling further (Take $500 cash and not flip a coin to win $1000)

When faced with a sure loss: Most people will gamble on an outcome to avoid the sure loss. (Don’t pay $500, and will flip a coin to maybe lose $1000)

Over my practicing career, this is something I have observed countless times. A simple treatment plan (fillings, cleaning) that would cost a small-moderate amount of money will often be neglected and the outcome will be gambled upon by the patient. Sometimes the gamble will pay off and the cavity or gingivitis will stabilise spontaneously. Sometimes the gamble won’t pay off and expensive outcomes will eventuate. The risk: reward isn’t symmetrical though, as most complex treatments like root canals, crowns, implants are significantly more expensive than fillings.

I’m not trying to advocate blindly following instruction by a health professional either. Procrastination can sometimes lead to better outcomes. I have a small cavity that I was told needed a filling back in dental school (2004). I procrastinated, and 15 years later its still the same size. Diligence and luck have probably played a factor.

My advice to anyone considering any form of dental treatment is this.

  1. Always get a second opinion (3rd opinion if it’s a large plan) – Multiple consults will pay for themselves.
  2. Once you’re happy with the plan, be aware of the fact that most people will psychologically flip a coin when faced with a sure loss.
  3. If you have decided to gamble on the outcome by not following through with treatment, make sure your oral hygiene, diet is excellent at home. Also, make sure you get regular reviews (at least yearly) to track progress and get feedback on your decision.

This line of thought could apply to many of life’s decisions. Building a house, visiting your car mechanic or deciding whether your small business is still viable!


Dr Max Ganhewa
BDS Otago, NZ
Registered with AHPRA, Member of the Australian Dental Association, Victorian Dental Association, and Australian Endodontic Society, Invisalign certified, 

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Being a dentist in the Melbourne CBD, many of Melbourne’s great attractions are at the doorstep of our dental clinic. Admire the architecture of Flinders St. Station, shop in the Collins St. or Bourke St. shopping precincts or simply have a barista made coffee and relax along Degraves St.