Economic profit is, however, much more prevalent in uncompetitive markets such as in a perfect monopoly or oligopoly situation. In these scenarios, individual firms have some element of market power: Though monopolists are constrained by consumer demand, they are not price takers, but instead either price-setters or quantity setters. This allows the firm to set a price which is higher than that which would be found in a similar but more competitive industry, allowing them economic profit in both the long and short run.^[4][5]

The existence of economic profits depends on the prevalence of barriers to entry: these stop other firms from entering into the industry and sapping away profits,^[7] like they would in a more competitive market. In cases where barriers are present, but more than one firm, firms can collude to limit production, thereby restricting supply in order to ensure the price of the product remains high enough to ensure all of the firms in the industry achieve an economic profit.^[4][7][8]

In a single-goods case, a positive economic profit happens when the firm's average cost is less than the price of the product or service at the profit-maximizing output. The economic profit is equal to the quantity of output multiplied by the difference between the average cost and the price.