[Hermel]

Of course, there is always a trade-off. For example, it is not worth spending 100$ for a 1% reduction in the risk of getting a disease that costs 1000$ to cure. If you really believe that prevention always pays off, why aren't you wearing a helmet right now?

[nolok]

Very poor exemple. Him not wearing a helmet right now has nothing do to with costs, its about practicality and societal norms. Even on construction sites we had to makes laws saying it is mandatory or big fines to get people to wear them.

[Hermel]

Not all cost is of monetary nature. Wearing a helmet costs you comfort, agility, and time. That's why we only do it when the risks outweigh the costs. Which is exactly the point: sometimes the risks outweigh the costs of prevention, sometimes they do not. Thus, this was an excellent example.

[laci27]

You're right. Like all things in life, one should use common sense when interacting with the world. No one (i hope) wants to spend their budget irrationally. So in your example, I would let the doctor decide if that $100 is spend better on curing rather than preventing. And that 1% reduction you came up as an example is not 1% for the entire population, it may be 1% to me and you, but maybe 50% for someone older, or with a specific condition...

[soVeryTired]

What makes you think I'm not?