Risk is often seen as the likelihood of an event occurring. i.e. what is the mathematical probability of a particular outcome. However, we humans rarely make our decisions based on mathematics but n emotions. And emotions are subjective.

I placed a thick wooden beam 3 meters long (10 foot) and 30 cm square section between two dining chairs. On one end I put a £20 note. Everything was solid and the beam was inflexible. I asked for a volunteer to walk the beam and if they did they could keep the £20 note. Everyone volunteered. So rather than select I suggested we raise the height. When I reset the height to 2 meters 80% of the class dropped out. However, I still didn’t want to make a selection so I raised it to 6 meters. I was left with one volunteer. All the rest thought the risk was too great. Yet the risk of falling was exactly the same. It was the perceived severity of harm that a fall would cause that was the significant influential factor in the attendees acceptance of the risk. Risk is not as much about mathematics as it is about the individual’s perception between loss and reward. However, their position wasn’t fixed as when I increased the amount of money on offer the class again volunteered on mass. I even suggested that I put the beam between two buildings 200 meters above the ground and as long as the reward was significant I had volunteers.

Wilf Archer

1.) Have £10 (is this a newly gained £10? An existing £10 out of the person's own pocket? How does this influence the person's state of mind).

2.) 50% chance of losing £10

3). 50% chance of gaining £20

It would be interesting to look at the starting point - ie does it make a difference if they feel they have already "won" by being given £10 or is it money they've "hard earned", as this is a part of option 1).

But that is not what the premise implies: 'Imagine your country is preparing for the outbreak of a disease expected to kill 600 people.' That looks like an absolute 600 to me. No hint of repetition in that.

It should have read something like: '600 people of every (e.g.) 10.000...' and: '200 of every 10.000 will be saved".

Sorry to be such a bore, but my point is this: how can you draw conclusions from a test that can be (mis)interpreted in more ways than the 2 it intended to test?

Imagine you repeat the scenerio three times. When you choose program A, 3 x 200 = 600 people die.

When you choose program B 3 times, the probability is that twice no one dies and one time 600 people die.

So the total number of people dying, on average, is the same - which means the 'expectation value' is the same.

Scarf, thank you!