Interrelated Markets

• Complements are goods that are in joint demand, also known as goods that are usually bought together, such as printers and printer ink, coffee machines and capsules, razors and blades.
• Substitutes are goods that are in competitive demand, also known as rival goods, which are very similar to each other and in competition with each other, such as coke and pepsi, big mac and the whopper, apple iphone and samsung galaxy.
• Joint supply is the idea that the increase in the production of one good will increase the supply of another good, because maybe that second good is a byproduct of the first one being produced, or because that second good needs the first good in order for it to be produced.
• Composite demand is the idea that two goods require the same input to make them, and therefore if there is an increase in the production of one good, there will be a decrease in the supply of the other because there is less of the input available to make the other good.
• Derived demand is the idea that when the demand for a good or service increases, the demand for the input used to produce it also increases.
• Derived demand is when the demand for a good or service comes from the demand for something else, it's derived from the demand for something else, such as aluminium, which is a demand derived from the demand for cars, labor, which is a demand derived from the demand for goods and services, and airline travel, which is a demand derived from the demand for holidays.