Competition (Economics)

Competition, in economics, is rivalry between firms that are trying to win the same customers, or between buyers trying to secure the same supplies. Firms compete on price, quality, service, convenience, speed and new ideas. The intensity of competition in a market shapes what consumers pay, how much is produced, how efficiently firms work and how quickly products improve.

Economists describe competition along a spectrum of market structures, from perfect competition, with many small price-taking firms, to monopoly, with a single seller. Most real markets sit in between. Governments protect competition through competition law, known in the United States as antitrust law, enforced by agencies such as the US Department of Justice, the European Commission and the UK Competition and Markets Authority (CMA).

Think of two pizza shops on the same street. If one raises its prices, cuts its portions or keeps customers waiting, people try the other. Each shop knows this, so each has a reason to keep prices fair, food good and service quick. If one invents a better pizza, the other has to respond or lose trade.

Now imagine the street has only one pizza shop and no other food for miles. It can charge more, take longer and try nothing new, and customers have little choice. Competition is the pressure that the first street has and the second lacks. It is not always comfortable for the shops, but it usually works in the customer's favor.

• Price competition. Firms cut prices or margins to win business. It is strongest when products are similar and buyers can compare prices easily.
• Non-price competition. Branding, quality, design, customer service, delivery speed and loyalty schemes. It dominates in markets with differentiated products.
• Competition through innovation. New products and methods replace old ones; Joseph Schumpeter called this creative destruction and saw it as the main source of long-run growth and innovation.
• Competition for the market. Where network effects are strong, firms compete to become the dominant platform, and the result can be a winner-takes-all market.
• Competition between buyers. Employers compete for workers and manufacturers for scarce inputs; weak competition on this side produces monopsony.

In an oligopoly or a duopoly, each firm must anticipate its rivals' reactions, which is why these markets are studied with game theory. Barriers to entry, such as licensing, economies of scale and intellectual property, decide how easily new rivals can appear.

Competition authorities often start with market concentration. The concentration ratio adds up the market shares of the largest firms (CR4 for the top four). The Herfindahl–Hirschman Index (HHI) sums the squares of every firm's market share:

• $s_i$ is the market share of firm $i$, in percent.
• $N$ is the number of firms in the market.

Worked example: a market with four firms holding 40%, 30%, 20% and 10% has an HHI of $1{,}600 + 900 + 400 + 100 = 3{,}000$. A pure monopoly scores 10,000; a market of 100 equal firms scores 100. The US 2023 Merger Guidelines, which the Federal Trade Commission and Department of Justice confirmed in February 2025 would remain in force, presume a merger illegal if it produces an HHI above 1,800 and raises it by more than 100 points.

Concentration is only a starting point. Authorities also look at price-cost margins, entry and exit, switching costs, how readily customers change supplier and whether firms earn persistently high returns.

Competition law typically prohibits cartels, abuse of a dominant position and mergers that would substantially lessen competition. In the United States the foundation is the Sherman Act of 1890; the European Union relies on Articles 101 and 102 of the Treaty on the Functioning of the European Union; India's Competition Commission enforces the Competition Act 2002, and Pakistan's Competition Commission the Competition Act 2010. In payments, competition concerns have led to caps on card interchange fees and to rules that open bank data and payment systems to new entrants.

Views on how hard to push differ. The Chicago school argues that markets usually correct themselves and that large firms are often large because they are efficient. Others argue that concentration has risen in many industries and that weak competition contributes to higher prices, lower wages and rent-seeking. Some economists warn that too much competition can be harmful in specific cases, such as natural monopolies or banking, where cut-throat rivalry may encourage excessive risk. Most agree that open entry and informed customers are the strongest protections.

• European Commission: Competition Policy
• UK Competition and Markets Authority
• US Department of Justice: Merger Guidelines