What are the various kinds of demand elasticity?

What are the four kinds or markets and their relationships to elasticity, inelasticity, supply and demand?

• Answer:

  The four markets are price-taker, monopolistic competition, oligopoly, and monopoly. The price taker market has many firms and is rather homogenous (the firms make one product alone). These goods are very inelastic, as the market usually determines the price, so charging more, people have many other firms to buy from. The monopolistic competitive is basically useless. I never teach people about it. It has many firms who sell very few products that are all close similarities. It has some features of a competitive market and monopoly market, but each firm has a monopoly on a good very similar to another. It is rather lightly elastic, as you can adjust your price, but there are still lots of competitors that will move in on your business. Usually, it is just the consumer's preference that prevents people from taking the cheapest product. Oh, they have free entrance and exit, unlike a monopoly. It is rather inelastic. Oligopoly are very few companies offering usually identical products. This one has a strange demand curve where above the "market price" it is elastic, but below, it tends to be inelastic. Monopolies have one firm offering one product. The demand is perfectly elastic as they have the ability to set whatever price they wish.