If an increase in the supply of beef increased the supply of hides, then beef and hides are in

The correct answer is "joint supply." When an increase in the production of beef leads to an increase in the supply of hides, it means that the two products are produced together as part of the same process. In other words, the production of one good generates the production of the other good as a byproduct. This is known as joint supply. Therefore, when there is an increase in the supply of beef, there will automatically be an increase in the supply of hides as well, and vice versa. This is because both goods are produced together and cannot be easily separated. It's important to note that joint supply is different from competitive supply, where two or more goods are produced using the same resources and compete for those resources. Joint supply is also different from composite supply, where two or more goods are combined to create a new product. Finally, joint demand refers to two or more goods that are demanded together, such as cars and gasoline.