> There is no real financial incentive to prevent cancer etc, but lots of money and glory for curing people who have got cancer.
Prevention is much harder to sell than cures because the effect of prevention is hard for people to see. If you get cancer, are given a treatment, and you live, you assume that without the treatment you would have died (death being the "counter-factual" observation that corresponds to the factual observation of your not dying), and thus that the treatment effect was big and important. But if you take a preventative treatment and don't get cancer, you don't have an obvious counter-factual to which you can compare your present state of well-being. You don't have the opportunity to realize that without the preventative treatment you would have gotten cancer and died: that counter-factual history never had a chance to play out.
Prevention is much harder to sell than cures because the effect of prevention is hard for people to see. If you get cancer, are given a treatment, and you live, you assume that without the treatment you would have died (death being the "counter-factual" observation that corresponds to the factual observation of your not dying), and thus that the treatment effect was big and important. But if you take a preventative treatment and don't get cancer, you don't have an obvious counter-factual to which you can compare your present state of well-being. You don't have the opportunity to realize that without the preventative treatment you would have gotten cancer and died: that counter-factual history never had a chance to play out.