Notes/BBS/Product Pricing: Theories and Practices
BBSUnit 7

Product Pricing: Theories and Practices

  • Product pricing theory examines how price and output are determined under different market structures. This unit covers the characteristics of perfect competition, monopoly, monopolistic competition, and oligopoly
  • the equilibrium of the firm under each
  • cartels and joint profit maximisation
  • real-world pricing practices including price discrimination, cost-plus pricing, and penetration pricing.

Market Structure: Concept and Characteristics

The way price and output are determined depends on the market structure — how firms are organised. Market structure refers to the characteristics or structural variables of the market that affect managerial decisions: the number of firms, the relative size of firms, technological and cost conditions, demand conditions, and the ease of entry and exit. Economists classify markets into four main structures: perfect competition, monopoly, monopolistic competition, and oligopoly.

Comparison of Four Market Structures

FeaturePerfect CompetitionMonopolyMonopolistic Comp.Oligopoly
Number of firmsVery manyOneManyA few
ProductHomogeneousUnique, no substitutesDifferentiatedHomo or differentiated
PricePrice takerPrice makerSome price powerPrice maker/seeker
Entry/ExitFreeBlockedFreeRestricted
AR curveHorizontalDownward slopingDownward, elasticKinked / interdependent
ExampleAgriculture, forexNEA, NOCRestaurants, soapAirlines, cement

Perfect Competition

Under perfect competition, there are many buyers and sellers, the product is homogeneous, there is free entry and exit, and all participants have perfect information. Each firm is a price taker — it cannot influence the market price and faces a horizontal (perfectly elastic) demand curve at the market price. In the short run, the firm maximises profit where MR = MC = P. It can earn supernormal profit (P > AC), normal profit (P = AC), or loss (P < AC). In the long run, free entry and exit drive economic profit to zero: P = min AC.

QPOP=AR=MRMCATCQ*
Perfectly competitive firm equilibrium: P = MR = MC, with AR tangent to AC.

Perfect competition equilibrium conditions

Monopoly

A monopoly is a market structure with a single seller of a product that has no close substitutes. The word comes from Greek 'monos polein' meaning 'alone to sell'. The monopolist is a price maker — it faces the entire market demand curve, so AR slopes downward and MR lies below AR. High barriers to entry (legal, technical, or natural) protect the monopoly. Equilibrium occurs where MR = MC (MC cuts MR from below), and price is read off the AR curve — typically above MC, creating deadweight loss.

QPOARMRMCP*Q*
Monopoly equilibrium: MR = MC determines quantity; AR determines price.

Welfare Loss of Monopoly

Compared to perfect competition, a monopolist produces less and charges more. The gap between the monopoly price and MC, applied to the lost output, is the deadweight loss — a pure loss to society that nobody captures. This is why governments regulate monopolies (e.g., Nepal Electricity Authority).

Monopolistic Competition

Monopolistic competition has many sellers, differentiated products (by brand, quality, design), relatively free entry and exit, and significant non-price competition (advertising). Each firm has a limited monopoly over its own brand but faces competition from similar products — so its AR curve is downward-sloping but more elastic than a monopolist's. In the short run, firms can earn supernormal profit; in the long run, entry erodes it to zero, with the AR curve tangent to the AC curve.

Oligopoly and Cartels

Oligopoly is a market with a few sellers of homogeneous or differentiated products. The key feature is mutual interdependence — each firm's decisions affect the others, so firms must consider rivals' reactions. This gives rise to the kinked demand curve (demand is more elastic above the current price, less elastic below) which explains price rigidity. A cartel is a formal agreement among oligopolists to act as a monopoly — jointly maximising profit by restricting output and raising price. OPEC is the best-known example.

QPOD = ARMRMCPcQcQ*CartelCompetitive
Cartel pricing: firms jointly act as a monopoly to maximise joint profit.

Pricing Practices

In the real world, firms follow various pricing strategies beyond the MR = MC rule. Price discrimination is selling the same product at different prices to different customers (possible only under monopoly power with separable markets and different elasticities). Cost-plus pricing adds a markup to average cost. Penetration pricing sets a low initial price to enter a market. Skimming pricing sets a high initial price that is gradually lowered. Predatory pricing sets prices below cost to drive competitors out.

Q₁P₁AR₁MCP_HMarket 1 (inelastic)Q₂P₂AR₂P_LMarket 2 (elastic)
Price discrimination: charging different prices in markets with different elasticities.

Degrees of Price Discrimination

  • First degree (perfect): the monopolist charges each consumer their maximum willingness to pay — all consumer surplus is captured. Example: lawyer's or doctor's fees.
  • Second degree: different prices for different quantities purchased — block pricing. Example: electricity and telephone tariffs.
  • Third degree: different prices for different consumer groups (with different elasticities). Example: student discounts, senior citizen fares.

Practice Problem

A monopolist faces the demand curve P = 100 − 2Q and has a constant marginal cost MC = 20. (a) Find the profit-maximising price and quantity. (b) Calculate the monopolist's profit. (c) Calculate the deadweight loss compared to the competitive outcome (P = MC).

Kinked Demand Curve (Oligopoly)

The kinked demand curve model, developed by Paul Sweezy (1939), explains price rigidity in oligopoly. The demand curve facing an oligopolist has a kink at the current price. Above the kink, demand is elastic (if the firm raises its price, competitors do not follow, so it loses many customers). Below the kink, demand is inelastic (if the firm cuts its price, competitors match the cut, so it gains few customers). The result: the firm has no incentive to change its price in either direction — prices are sticky. The corresponding MR curve has a discontinuity (vertical gap) at the kink quantity, which allows MC to fluctuate without changing the profit-maximising price.

QPODKMRMC
Kinked demand curve: elastic above the kink, inelastic below — explaining price rigidity.

Price Discrimination: Conditions and Degrees

  1. the firm has monopoly power (price maker)
  2. the market can be divided into sub-markets (no resale between them)
  3. different sub-markets have different price elasticities of demand. The firm charges a higher price in the less elastic market (where buyers are less sensitive) and a lower price in the more elastic market. The third-degree discrimination (charging different groups different prices) is the most common — e.g., student discounts, senior citizen fares, different prices in domestic vs export markets

Three Degrees of Price Discrimination

DegreeBasisConsumer Surplus CapturedExample
First (Perfect)Each unit sold at max willingness to payAll (100%)Doctor/lawyer fees
SecondDifferent prices for different quantitiesPartial (block pricing)Electricity tariff
ThirdDifferent groups pay different pricesPartial (group-based)Student/senior discount

Real-Life Example: Nepal Telecom

Nepal Telecom (NTC) practices price discrimination. It charges different rates for: off-peak vs peak hours (time-based), prepaid vs postpaid plans (customer type), corporate vs individual users (market segmentation), and domestic vs international roaming (geographic). NTC can do this because it has significant market power, can separate markets (SIM registration prevents resale), and different segments have different elasticities (business users are less price-sensitive than students).

Common Misconception: NEA as Monopoly

Nepal Electricity Authority (NEA) is a classic example of a government monopoly. It is the sole producer and distributor of electricity in Nepal. This creates deadweight loss — NEA produces less and charges more than a competitive market would. However, electricity is a natural monopoly (high fixed costs, economies of scale mean one firm is most efficient), so competition would be wasteful. This is why NEA is regulated by the government rather than broken up — regulation aims to achieve the low prices and high output that competition would provide.

Key Terms and Definitions

  • Market structure: Organisational characteristics of a market — बजार संरचना: बजारका संगठनात्मक विशेषता।
  • Perfect competition: Many firms, homogeneous product, free entry — पूर्ण प्रतिस्पर्धा: धेरै फर्म, समरूप उत्पादन, स्वतन्त्र प्रवेश।
  • Monopoly: Single seller, no close substitutes, price maker — एकाधिकार: एकल विक्रेता, नजिकको विकल्प छैन, मूल्य निर्धारक।
  • Monopolistic competition: Many firms, differentiated products — एकाधिकारी प्रतिस्पर्धा: धेरै फर्म, विभेदित उत्पादन।
  • Oligopoly: A few firms, mutual interdependence — अल्पाधिकार: केही फर्म, पारस्परिक अन्तरनिर्भरता।
  • Cartel: Formal agreement among oligopolists to act as monopoly — कार्टेल: एकाधिकारका रूपमा कार्य गर्ने अल्पाधिकारीहरूको औपचारिक सम्झौता।
  • Price discrimination: Same product at different prices to different buyers — मूल्य भेदभाव: उही उत्पादन विभिन्न खरिदकर्तालाई फरक मूल्यमा।
  • Deadweight loss: Welfare loss from market power — मृतभार हानि: बजार शक्तिबाट कल्याणकारी हानि।
  • Kinked demand curve: Explains price rigidity in oligopoly — मोडिएको माग वक्र: अल्पाधिकारमा मूल्य कठोरता व्याख्या गर्छ।
  • Natural monopoly: Industry where one firm is most efficient — प्राकृतिक एकाधिकार: एक फर्म सबैभन्दा कुशल हुने उद्योग।

Practice Problem

A monopolist sells in two markets A and B. The demand functions are: QA = 100 − 2PA and QB = 80 − 4PB. The monopolist has a constant MC = Rs 10. (a) Find the profit-maximising price in each market (third-degree price discrimination). (b) Calculate the quantity sold in each market. (c) Verify that the market with lower elasticity gets the higher price.