Externalities are the costs of making something that are not paid for by the manufacturer. They can be subsidies, pollution that someone else has to clean up or live with, health costs… The goal of manufacturers is to make as many of their costs as possible external.
The degree of success is astounding. A $1 fast food hamburger would cost $200 if the externalities were included. The US government subsidises the fossil fuel industry to the tune of $10 million a minute. This is not a wise policy when we are supposedly trying to encourage the public to reduce greenhouse gas emissions and switch over to clean energy.
These businesses are so profitable that they can buy politicians to increase the externalities.~ Roedy (1948-02-04 age:69)