ApproximateMechanism Design
Without Money
App. Mech. Design Without Money
• Mechanism
• Truthfulness
• Without money
2
VCG
Money is the root of all evil!
• Security issues
• Banking issues
• Ethical Considerations
• Legal Considerations
3
App. Mech. Design Without Money
• Mechanism
• Truthfulness
• Without money
• Approximation
4
VCG
Problem Classes
5
Opt Sp MechanismWith money
&Intractable
Class 1Opt SP Mechanism
With moneyIntractable
Class 2No Opt SP
Mechanism With Money
Class 3No opt SP Mechanism
Without Money
Picture is from slides of [1]
Facility Location - Definitions
• Network, Graph
• Agents
• Location Profile
• Deterministic Mechanism
• Randomized Mechanism
• SP and GSP
6
Facility Location - Summary
7
Picture is from slides of [1]
Trees – Median is optimum
8
E
C
B
A
G
F
D
F
C
B
A
Picture is from slides of [1]
Facility Location - Summary
9
Picture is from slides of [1]
Social Cost
10
Facility Location - Summary
11
Picture is from slides of [1]
Maximum Cost
12
A By
Facility Location - Summary
13
Picture is from slides of [1]
Maximum Cost – Randomized UB
14
EDA C
1/4 1/2 1/4
BB
1/4 1/2
d2d
Picture is from slides of [1]
Facility Location - Summary
15
Picture is from slides of [1]
Election - Definitions
• Voters
• Candidates
• Preference List
• Preference Profile
• Approximation
16
Single• Mechanism
• Benefit
Election – Definitions (cont.)
17
Matching
• Mechanism
• Benefit
Election - Summary
18
Single – Deterministic UB
19
Single – Randomized UB
20
Matching
21
C1 C2
1 2 3 n
1
1 2 22
1
2
1
OPT=3
OPT’=4
?22
ThanksThanks
Refrences
1. N. Alon, M. Feldman, A. D. Procaccia, M. Tennenholtz. Strategyproof Approximation Mechanisms for Location on Networks. CoRR, 2009
2. A. D. Procaccia, M. Tennenholtz. Approximate mechanism design without money. In Proceedings of the 10th ACM Conference on Electronic Commerce (ACM-EC), 2009
3. J. Schummer and R. V. Vohra. Mechanism design without money. In N. Nisan, T. Roughgarden, E. Tardos, and V. Vazirani, editors, Algorithmic Game Theory, chapter 10. Cambridge University Press, 2007.
23
24
B
C
DE
1/4
F 1/2
1/4A
25
B3/8
B
A
CC
A
3/8
1/4