In both of the following cases, identify the type of externality that led policy-makers to implement regulations.

a. In 1992, the government of Singapore banned the importation and sale of chewing gum. This included bringing chewing gum into Singapore for personal use. (Note: This law was softened in 2004 following the United States–Singapore free trade agreement, which allowed certain chewing gums to be sold by pharmacies for therapeutic reasons.)

b. France has a law that portable listening devices must have a maximum output level of 100 decibels. Apple was forced to change the output of its iPods sold to France as their output exceeded 100 decibels.