Externality in Supersize Me

The main externality in the movie, Supersize Me, is the negative effect that the fast food industry has on a persons health. While McDonalds is selling food for a relatively cheap price, the negative effects the food will have on your body is terrible and will end up costing you more money in the long run. The definition of externality is the effect something will have on the surroundings. McDonalds is a very good example of a negative externality, it negatively effects the people's health.