1. 1 Industrial Organization Collusion Univ. Prof. dr. Maarten Janssen University of Vienna Summer semester 2013 - Week 17

2. 2 Different Issues What are the incentives to form a cartel? In a given industry, how many firms will form a cartel if binding agreements can be made? What makes it that cartel members stay within the cartel? All three issues will be dealt with separately in three parts

3. 3 1. Incentives for Collusion

4. 4 Q2Q2 Q1Q1 Q1MQ1M r1r1 Q2*Q2* Q1*Q1* Firm 1’s Profits Firm 2’s Profits r2r2 Q2MQ2M Scope for collusion Scope for Collusion with quantity choice

5. 5 Scope for Collusion under price setting R 1 (p 2 ) R 2 (p 1 ) Scope for colusion p2Bp2B p1Bp1B p2p2 p1p1

6. 6 2. How many firms will form a cartel?

7. 7 Not an obvious answer N=2, answer is clear General N, less obvious  A noncartel firm benefits from cartel as cartel internalizes externality Output reduction in case of Cournot Price increases in case of (differentiated) Bertrand  Cartel members have to share the cartel profits among themselves; the more there are, the less for each member

8. 8 Consider the question in Cournot context with cartel as market leader P = 1 – Q; no cost N firms in industry, n firms in cartel Individual profit of a firm not belonging to cartel: (1 – nq c – (N-n)q)q, where q c (q) is output individual cartel (noncartel) member Individual reaction noncartel firm: 1 – nq c – (N- n-1)q - 2q = 0, or q = (1 – nq c )/(N-n+1) Given this reaction cartel maximizes (1 – nq c )q c /(N-n+1) wrt q c or q c = 1/2n  Individual output noncartel firm: q = 1/2(N-n+1)

9. 9 How many firms in Cournot setting II Profits of cartel and noncartel firms:  Cartel members π c (n): 1/4n(N-n+1)  Others π(n): 1/4(N-n+1) 2 Firms want to join cartel as long as this yield more profits, i.e., when π(n) < π c (n+1)  1/(N-n+1) 2 < 1/(n+1)(N-n) Firms want quit the cartel as long as this yield more profits, i.e., when π(n-1) > π c (n)  1/(N-n+2) 2 > 1/n(N-n+1) For example when N = 10, cartel with 6 members is stable. Non-cartel members also benefit from cartel and stability requires their profits to be very similar to that of cartel members!

10. 10 3. Why stick to the cartel agreement?

11. 11 Collusion Refers to firm conduct intended to coordinate the actions of other firms in the industry Two problems associated:  Agreement must be reached  Firms must find mechanisms to enforce the agreement

12. 12 Types of collusion Cartel agreements: an ‘institutional’ form of collusion (also called explicit collusion or secret agreements)  Unlawful (Sherman Act and Art. 85 Treaty of Rome)  Requires evidence of communication Tacit or Implicit collusion: attained because firms interact often and ‘find’ ‘natural’ focal points.  This second type make things complicated for antitrust authorities Focus on latter

13. 13 Example of collusion General Mills Kellogg’s

14. 14 Can collusion work if firms play the game each year, forever? Consider the following “trigger strategy” by each firm:  “Don’t advertise, provided the rival has not advertised in the past. If the rival ever advertises, “punish” it by engaging in a high level of advertising forever after.” In effect, each firm agrees to “cooperate” so long as the rival hasn’t “cheated” in the past. “Cheating” triggers punishment in all future periods.

15. 15 Suppose General Mills adopts this trigger strategy. Kellogg’s profits?  Cooperate = 12 +12/(1+i) + 12/(1+i) 2 + 12/(1+i) 3 + … = 12 + 12/i General Mills Kellogg’s Value of a perpetuity of $12 paid at the end of every year  Cheat = 20 +2/(1+i) + 2/(1+i) 2 + 2/(1+i) 3 + = 20 + 2/i

16. 16 Kellogg’s Gain to Cheating:  Cheat -  Cooperate = 20 + 2/i - (12 + 12/i) = 8 - 10/i  Suppose i =.05  Cheat -  Cooperate = 8 - 10/.05 = 8 - 200 = -192 It doesn’t pay to deviate.  Collusion is a Nash equilibrium in the infinitely repeated game! General Mills Kellogg’s

17. 17 Benefits & Costs of Cheating  Cheat -  Cooperate = 8 - 10/i  8 = Immediate Benefit (20 - 12 today)  10/i = PV of Future Cost (12 - 2 forever after) If Immediate Benefit > PV of Future Cost  Pays to “cheat”. If Immediate Benefit  PV of Future Cost  Doesn’t pay to “cheat”. General Mills Kellogg’s

18. 18 Key Insight Collusion can be sustained as a Nash equilibrium when there is no certain “end” to a game. Doing so requires:  Ability to monitor actions of rivals  Ability (and reputation for) punishing defectors  Low interest rate  High probability of future interaction

19. 19 Collusion in Cournot and/or Bertrand Π i (s i,s -i ) firm’s profit given strategies of all firms Π i * = Π i (s* i,s* -i ) static Nash equilibrium profits There are strategies s’ i,s’ -i s.t. Π i ’ = Π i (s’ i,s’ -i ) ≥ Π i (s* i,s* -i ), usually leading to higher prices and lower consumer benefits Can these strategies be sustained in an infinitely repeated game?  Trigger strategies: do your part of the combination (s’ i,s’ -i ) as long as all other players do so, otherwise refer forever after to your part of (s* i,s* -i )  Alternatively, tit-for-tat

20. 20 Equilibrium condition π is best possible static deviation pay-off Equilibrium condition: Π i ’/(1-δ) ≥ π + δΠ i */(1-δ) if everyone has the same discount factor Alternatively δ ≥ (π - Π i ’)/(π - Π i *). Generally depends on N: the more firms the more stringent the requirement on δ.

21. 21 Collusion is more likely with fewer firms in homogeneous product markets with more symmetric firms in markets with no capacity constraints in very transparent markets (cheating is seen easily)  no hidden discounts  no random demand; low demand can be because of cheating others or because of low realization of demand  observability lags; if you can get cheating pay-off for more than 1 period equilibrium condition becomes: Π i ’/(1-δ) ≥ (1+δ) π + δ 2 Π i */(1-δ) or δ ≥ {(π - Π i ’)/(π - Π i *)} 1/2.