Skip to main content

Microeconomics: monopoly

Definition of the term monopoly:

A monopoly is a firm that is the only supplier of a unique good or service in a market.
  • Monopoly markets have barriers to entry, which prevents other firms from entering the market and competing with the monopolistic firm.
  • Since monopolies do not have to compete with other producers, they have a strong influence over the price and quantity in their markets, only limited by consumer's demand.
Factors that cause monopoly power:

  • Geography; a remote and isolated area might only have one grocery store. Because the store lacks competition, it is able to charge significantly higher price for its produce than stores that face competition.
  • Government monopoly; when the government entirely provides a good or service. For example, a local government might decide to have a public trash collection service.
  • Natural monopoly: it exists if and only if a firm experiences extreme economies of scale and is able to serve the market more cheaply than any other firms. Example, utility companies (water,gas, and electricity).
  • Legal barriers; a firm can become a monopoly when the government grants a patent or copyright to a single company.
Monopoly: demand, and marginal revenue

Because the monopolistic firm is the only firm in the market, it faces the entire down sloping demand curve. In this case, the total revenue curve forms a concave parabola (TR= Q*P(Q)). To find the maximum revenue, just find where the MR (marginal revenue) is equal to zero.
  • Revenue is maximized when the demand curve is unit elastic ( equal to 1).

Profit Maximization:

  • Just like in a competitive firm model, a monopolistic firm maximizes its profit by producing where its MC is equal to its MR. 
  • However, unlike a competitive firm, the MR is not equal to the price, instead once the quantity which satisfies the MR=MC relationship is found, plug this quantity (Q*) into the demand function and solve for the price.
  •  Profit corresponds to a rectangular area, where the height is equal to the distance between ATC and the demand curve and the length equals to Q*.

Inefficiency:


  • Productive inefficiency:
    1. A monopoly does not produce at the lowest point on the ATC. Therefore, it is not productively efficient.
  • Allocative inefficiency:
    1. A monopoly price is greater than the marginal cost of production. Therefore, a monopolistic firm will produce less than a market with perfect competition. Notice that a perfectly competitive market produces where MC equals demand. This result in a dead-weight loss created by the monopoly (see graph).


The reader should notice that there is something wrong with my MC curve, since it does not intersect at the minimum of the ATC. This is because I chose to use a function that is similar to the real MC but makes the pattern observed in a monopoly more obvious.

Reference: Mayer,David. AP Microeconomics Crash Course. Research & Education Association (2014). p 101-106. 





Comments

Popular posts from this blog

Macroeconomics: multiplier and crowding out effects

Multiplier effect: whenever   any of the components of AD increases, the increase in GDP will be greater than the initial increase in expenditures. The impact on GDP of a particular increase in spending depends on the proportion of the new income that is taken out of the system to the proportion that continues to circulate in the economy. The multiplier effect tells us the impact a particular change in one the components of AD will have on the total income (GDP).  Let k denote the spending multiplier, which is a function of MPC and MPS. The larger the marginal propensity to consume, the larger the spending multiplier. Notice that the larger the MPC, the greater the impact a particular change in the spending variables will have on the nation's GDP. The crowding out effect: If government spending increases without an increase in taxes, the government must borrow funds from the private sector to finance its deficit, thereby increasing the interest rate. This increase in interest ...

Microeconomics: Factor Markets

Definition: Factor markets: markets for the factors of production (example: labor and capital). Markets are formed whenever consumers and producers meet to exchange goods or services. Deriving factor demand: the demand for goods or services in the product markets creates demand for the factors of production.  An increase (decrease) in demand for good X leads the suppliers to increase their production thereby increasing (decreasing) the demand for the factors of production.   Marginal revenue product: The demand for the factor of production is formed by multiplying a firm's marginal revenue by its marginal product.  Remember that by taking the derivative of the TR function with respect to Q we are able to find the MR. Marginal product on the other hand is found by taking the derivative of the production function with respect to a factor of production (L or K for example). Marginal revenue product (MRP): the change in total revenue when one more input is employed. It decrea...

Macroeconomics: foreign exchange market

A currency exchange rate tells us about the value of a currency relative to another currency.  We say that a currency appreciates when its relative value goes up. We say that a currency depreciates when its relative value decreases. In a market that relates two currencies, if one appreciates, it must be the case that the other currency depreciates.  Demand in the foreign exchange market: it represents the quantity of a currency demanded by agents who are holding other currencies. The agents want to buy goods, services, or financial assets from a country whose currency is demanded. The demand must be downward slopping. The weaker the currency, the more attractive the goods produced in that country are, and foreign consumers need to hold more of that currency in order to buy the products. Thus, a change in the exchange rate leads to a movement along the demand curve. Supply in the foreign exchange market: it represents the willingness of people in the country supply to foreigner...