What is one effect of high barriers to entry in an oligopoly?

High barriers to entry in an oligopoly indeed decrease competition among existing firms. When substantial barriers, such as significant startup costs, strong brand loyalty, or government regulations, are present, it becomes difficult for new competitors to enter the market. As a result, the existing firms face little threat from new entrants, allowing them to maintain their market share and pricing power without the pressure that new competition typically brings.

With fewer competitors in the market, the existing firms can engage in practices like collusion or price-setting behavior, which can further reduce competition and lead to higher prices for consumers compared to a more competitive market structure. This scenario ultimately reinforces the dominance of existing firms, allowing them to behave more like a monopoly than an open market, which is characteristic of oligopolies where high barriers to entry are prevalent.