This is critical, because it makes them actually price-sensitive. You can't choose not to have heart disease, though.
Free markets have a bunch of conditions on their efficiency that are often ignored by advocates and don't always apply: must be plurality of non-coordinated buyers and sellers, must be feasible for participants to determine quality of goods (Akerloff's "lemons"), must be low barriers to entry, must be feasible for participants to choose not to do a transaction, and so on.
This is critical, because it makes them actually price-sensitive. You can't choose not to have heart disease, though.
Free markets have a bunch of conditions on their efficiency that are often ignored by advocates and don't always apply: must be plurality of non-coordinated buyers and sellers, must be feasible for participants to determine quality of goods (Akerloff's "lemons"), must be low barriers to entry, must be feasible for participants to choose not to do a transaction, and so on.