A market structure in which a single producer supplies a unique product that has no close substitutes. In an unregulated monopoly, the producer sets the prices
One producer, unique, high barrier to entry, substantial control over prices
US Postal Service
Sirius XM
A market structure in which many producers supply similar but varied products. This structure is the closest to perfect competition.
A market structure in which many producers supply an identical product. This is the most efficient structure, with prices set by supply and demand.
Toothbrushes
A market structure in which a few firms dominate the market and produce similar or identical goods. This is more competitive than an monopoly.
Examples
Many producers, differentiated products, few barriers to entry, some control over prices.
Plates
Produce
Many producers and consumers, identical products, easy entry, no control over prices.
Cotton
Car Manufacturers
Few producers, similar product, high barriers to entry, some control over prices
Oil