1. Mandatory minimums lead to competing increasing drug purity. When there is a per unit tax, people switch from the taxed margin (quantity) to the untaxed margin (quality).
2. A racial gap in condom use. This is tricky. More condom use among African American males does not lead to less disease. It may in fact be a response to higher disease incidence. They also have a higher degree of concurrent partners. Make no mistake, this has only very little to do with race, and a lot to factors correlated with race, such as sex ratios, education, etc.
3. Beware of substitution effects. When the price of one drug goes up, addicts substitute.
4. Technology and health. Even as technology promises to improve our health outcomes, it has a dark side. At worst it can kill the patient. Or it can cure the patient of an ailment that would never have killed the patient (by killing a slow growing tumor), thus making its marginal efficacy in terms of increasing life zero, yet its cost is far from zero. Still at other times the technology might just be overused.