Under perfect competition neither consumers nor producers have market power (they can’t influence the price) so the producers’ decision boils down to only choosing the level of output that maximizes their profits. And conditions are such that they maximize profit at a higher output than if they where monopolists.
On the other hand, monopolist have market power so they decide over two variables: price and output. In this case, they can make more profits by charging a higher price and producing a lower output.
This is why monopolies reduce social welfare because by limiting their output they are preventing some to have access to a scarce good and making it inaccessible for others to consume the good because of its high price, compared to perfect competition where prices are lower and output is larger, which would be more efficient than a monopoly because no resources are being squandered or under-used.
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Well monopoly is the absence of competition. Monopolistic firms can maximize profits by producing less of the good than the amount demanded- causing the price to be higher. If the firm was facing competition if would produce more of the good and the price would be lower.
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competition is efficient cuz customers gets to choose. in monopoly, ppl have can not choose, so the vendors can sell the product at a high price if they want. if the products r not elastic, ppl will b forced to buy that product