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Efficient Handicap Auction
(Old version: The 40%-Handicap Auction)
Yosuke YASUDA
Osaka University, Dept. of Economics
December, 2015
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The Paper is About ...
Efficient design of license auctions�� ��Ex Spectrum auctions
Auctions design: Competition in the auction⇐ Game Theory
Entry regulation: Competition after the auction⇐ Industrial Organization
Connecting two competitions in a single unified model.�� ��Q What is efficient way to provide licenses?�� ��A Use the (40%) handicap auction!
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Introduction
Government can influence markets by allocating licenses.
(Direct Control ⇒) “Beauty Contest” ⇒ License Auctions
Advantages: efficiency, revenue, transparency, speed . . .
Real life examples of license auctions:
Bus routes
Radio spectrum rights
Airport slots
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How many licenses to provide/sell?
The government can choose the # of licenses to provide.
Auctions likely achieve efficiency given the # of licenses.
Usual Efficiency = maximizing winners’ valuations
Efficiency in this paper = maximizing total welfare
Impossible to decide the optimal # prior to the auction.
market competition(many licenses)
vs. production efficiency(few licenses)
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Free entry is NOT efficient
Fact 1 (Excess Entry Theorem)
The equilibrium # of firms in an oligopoly market under free entryis greater than the efficient # of firms.
Symmetric firms with fixed costs:
Mankiw and Whinston (1986, Rand)
Suzumura and Kiyono (1987, REStud)
Asymmetric firms (with no fixed cost):
Lahiri and Ono (1988, EJ)
⇒ A weak rationale for entry regulation.
⇒ How to implement the optimal regulation in practice?
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Motivating Example
European UMTS (3G) Auctions
Spectrum auctions in European countries in 2000-01.
Each country sets a number of licenses
={
# of incumbent firms in 2G services# of — + 1
Effectively, “accepting a new entrant” or “not.”
⇒ Can we better choose the number?
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Simplest Setting: Monopoly or Duopoly
Consider a monopoly market.
The monopolist already has a license.
Government provides a second license or not:{No additional licenseProviding a license
⇒ Monopoly⇒ Duopoly
Either a monopoly or a duopoly can be efficient.
The costs are private information of the firms.
⇒ How to implement an optimal policy?
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The Benchmark Model
Homogenous good
Linear demand: p = a− bq
2 firms
{IncumbentNewcomer
: firm 1: firm 2
Cournot competition
Constant marginal costs: ci, i = 1, 2
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Welfare-Reducing Entry
Fact 2 (Lahiri and Ono, 1988)
Duopoly is more efficient than monopoly iff
c2 < c∗
where c∗ =5a + 17c1
22.{
c2 < c∗ (low-cost)c2 > c∗ (high-cost)
⇒ Social Welfare ↑⇒ Social Welfare ↓
See the next figures.
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The Beauty Contest
If the government knew the parameters a, c1, c2
⇒ Optimal policy can be implemented.
Otherwise, what can we do?
How about auctions?
English or second-price auction:{Firm 1 wins:Firm 2 wins:
⇒ Monopoly⇒ Duopoly
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Benchmark assumptions
The government maximizes social welfare (total surplus).
⇒ Generalized social welfare
The firms’ costs are common knowledge among firms.
⇒ Asymmetric information
The government can only control entry decision.
= Other (direct) regulations are excluded.
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Valuations for the license
Each firm’s valuation for the license:
v1 = πm − π1
v2 = π2
Truthful bidding is optimal (a dominant strategy).
Entry occurs iff
v1 < v2 ⇐⇒ πm − π1 < π2
⇒ Does this mechanism achieve efficiency?
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Symmetric Firms (c1= c2)
Duopoly is more efficient than monopoly.
However, the incumbent wins (Gilbert and Newbery, 1982).
⇐ The monopoly profit is larger than the duopoly (joint-)profit.
πm > π1 + π2 ⇐⇒ πm − π1 > π2 ⇐⇒ v1 > v2
Some kind of handicap favoring a newcomer is needed.
⇒ Think about “handicap” auctions!
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Handicap (English) Auction with H
The auction stops when one firm drops out.
The remaining bidder is the winner who obtains the license.
⇒ Similar to an English auction.
Only the payment of the newcomer is different.{Incumbent:Newcomer:
Pay the winning price if it wins.Pay only H of the winning price if it wins
⇒ The newcomer’s optimal strategy becomes “biddingv2
H.”
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Benchmark Result
Theorem 3
The 40% handicap auction (H = 0.4) described as followsimplements entry iff duopoly is more efficient than monopoly.{
Incumbent:Newcomer:
Pay the winning price if it wins.Pay only 40% of the winning price if it wins
⇒ Why “40%”?
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The sketch of the proof
∆SW = ∆CS + ∆PS = ∆CS + π1 + π2 − πm
= ∆CS + v2 − v1 (SW)
∆CS can be expressed as follows (Lemma 3).
∆CS =v1
2+
v2
4
Substituting it into (SW), we obtain the result.
∆SW > 0 ⇐⇒ v1
2+
v2
4+ v2 − v1 > 0
⇐⇒ v1 <v2
0.4
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Remarks
Our auction is independent of the parameters, a, b, c1, c2.
Demand functions need NOT be globally linear.
Robustness: welfare loss caused by introducing non-linearity issecond order effect. (Akerlof and Yellen, 1985)
Efficiency is achieved by dominant strategies.
⇒ Independent of the cost distributions.
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Generalization
Asymmetric Information among firms
Non-linear costs & demand
Wealfare Loss: Numerical Results
Multiple incumbents (← if time remains)
No incumbent firm, i.e., new market (← Skipped)
General social welfare functions (← Skipped)
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Asymmetric Information
Two cases of asymmetric information.
Case 1: The newcomer’s cost is only privately known.
⇒ Reasonable situation.
Case 2: The both firms’ costs are private information.
⇒ Impossibility result. (← Skipped)
A government cannot observe firms’ costs.
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One-Sided Private Information
Theorem 4
The 40% handicap auction continues to achieves efficiency even ifthe newcomer’s cost becomes private information.
Solved by iterative dominance.
The newcomer has a dominant strategy, “biddingv2
0.4.”
⇒ What is the incumbent’s best response?
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Efficiency Result
For the incumbent, it is optimal to take the following biddingstrategy b1 (Lemma 4).
b1 = πm − π1(c1, c∗)
⇒ b1 = v1 iff b1 = b2
(=
v2
0.4
).
The same outcome and payoff as in the benchmark case.
⇒ No efficiency loss.
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Fixed Costs
Suppose a newcomer has a fixed set-up cost F .
C2(q2) ={
F + c2q2
0if q2 > 0if q2 = 0
The 40% handicap auction fails to achieve the first best whenF > 0 (Lemma 5).
⇒ Is there any efficient mechanism?
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Fixed Costs: Result
Theorem 5
Suppose the government can observe F . Then, the 40% handicapauction with the following conditional subsidy achieves efficiency.{
If the newcomer winsIf the incumbent wins
⇒ The subsidy of 0.2F⇒ No subsidy
The government need not know F prior to the auction.Instead, it is sufficient to observe it ex-post.
Implemented by “investment tax credit.”
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Quadratic Costs
Suppose firms have the following quadratic cost functions.
Ci(qi) =αq2
i
2+ ciqi i = 1, 2
The slope of the marginal costs α is common across the firms.{α < 0: concaveα > 0: convex
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Quadratic Costs: Result
Theorem 6
Suppose firms have the above quadratic costs, and the governmentknows α. Then the handicap auction with Hq achieves efficiency.
Hq =2
5 + 2α + α2+α
The optimal handicap Hq depends on α.α < 0: concave
α = 0: linear
α > 0: convex
⇒ Hq ↑
⇒ Hq = 0.4
⇒ Hq ↓
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When α is not known
The first best cannot be achieved.
What if the 40% auction is employed?{α < 0: concaveα > 0: convex
⇒ Never deter welfare increasing entry⇒ Never accept welfare decreasing entry
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Efficiency Loss
The optimal handicap H∗ is different from 40% in non-linearcases.
If we employ the 40% handicap auction in non-linear cases,then{
How likely is an inefficiency?How big is the expected efficiency loss?
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When Does Inefficiency Happen?
Under the optimal rule{ v2H∗ < v1 ⇔ v2
v1< H∗
v2H∗ > v1 ⇔ v2
v1> H∗
⇒ Monopoly⇒ Duopoly
Under the 40% handicap auction{ v2v1
< 0.4v2v1
> 0.4⇒ Monopoly⇒ Duopoly
Inefficiency happens iff{H∗ < v2
v1< 0.4 if H∗ < 0.4
0.4 < v2v1
< H∗ if H∗ > 0.4⇒ Deter desirable entry⇒ Accept undesirable entry
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Numerical Results
Fixed costs with F =12π2.
Then, the optimal handicap H∗ is13.
Assume the following distribution.
v1 = 1, v2 ∼ U [0, 1]
⇒ No entry under the English auction.
An inefficient outcome occurs with 7% .
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Expected Social Welfare
The previous analysis did not consider the impact ofinefficient outcomes.
⇒ How big is the expected efficiency loss?
Expected social welfare under each policy.
V ∗ =∫ H∗
0SWmdv2 +
∫ 1
H∗SW ddv2
V 40 =∫ 0.4
0SWmdv2 +
∫ 1
0.4SW ddv2
V m =∫ 1
0SWmdv2
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Expected Welfare Loss
Relative performance of the 40% auction.
RP ≡ V 40 − V m
V ∗ − V m≤ V 40
V ∗ ≤ 1
In our example, RP is 0.99.
⇒ The expected loss is just 1%!
The expected loss of social welfare is much smaller than 7%.
⇒ |∆SW | is relatively small when inefficient outcomeshappen.
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Multiple Incumbents
Suppose there are n incumbents.
European UMTS Auctions{The number of incumbents in 2G services ( = n)One more than it ( = n + 1)
⇒ Can we apply our handicap auction?
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Multiple Incumbents: Result 1
Theorem 7
Suppose the incumbents are allowed to bid as a group and toprovide a single bid. If they can fully cooperate for bidding, thenthe handicap auction with Hm achieves efficiency.
Hm =n + 12n + 3
We do NOT assume incumbents are symmetric.
Even so, Hm depends only on n, not on c1, ..., cn.
Cooperative bidding resolves “free-rider problem.”
⇒ Fixed costs?
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Multiple Incumbents: Result 2
Theorem 8
Suppose all the conditions stated in Theorem 7 are satisfied and Fis observed by the government. Then, the combination of thehandicap auction with Hm and the following conditional subsidyachieves efficiency.{
If the newcomer wins
If the incumbent wins
⇒ Subsidized by 12n+3F
⇒ No subsidy
The subsidy converges to 0 as n→∞.
⇒ Is cooperation possible?
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Pre-Auction Mechanism (among the incumbents)
Each incumbent chooses bi ∈ [0, vi].
The incumbents bidn∑
i=1bi in the auction and each incumbent
paysvi
n∑j=1
vj
of the winning price it they win.
⇒ This mechanism implements cooperative bidding.
Risk of collusion after the auction.
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Conclusion
An extremely simple efficient license auction is proposed.
Can be generalized in many situations.
Efficiency losses in non-linear cases are quite small.
⇒ Contribution to practical market design.
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