I don't know that they have high barriers to exist. But they usually do have high barriers to entry. It's "tough" because other companies can't compete. It's usually too expensive for a start up company to even try. Related to monopolies are oligopolies,
It's ruling by the few. An example of an oligopoly is the cell phone companies. There are only a few cell phone companies because it's cost prohibitive to enter into the cell phone market.
Perfect competition
c) no barriers to entry or exit in the long run
security barriers
The idea of a perfectly competitive market is that no one business or entity is large enough to hold power over a market or product. Zero entry and exit barriers make this possible, because it means that the market is ever changing as businesses fail and new companies emerge.
Under pure competition there are large number of buyers and sellers, homogeneous products and free entry and exit. Whereas under Monopoly there is a single seller, there are no close substitutes for the commodity it produces and there are barriers to entry.
what are the entry barriers in pharmaceutical industry?
aaa
Perfect competition
c) no barriers to entry or exit in the long run
security barriers
There is a entry in the door way. Every doorway has an exit sign to show you where to go out. The castle had a huge entry.
There were many external environments that affected Merck company. They were rivalry, entry and exit barriers, supplier power, buyer power and threat of substitutes.
The idea of a perfectly competitive market is that no one business or entity is large enough to hold power over a market or product. Zero entry and exit barriers make this possible, because it means that the market is ever changing as businesses fail and new companies emerge.
An antonym for the word 'entry' is 'exit'.
An electrical burn will cause entry and exit wounds.
exit
yes