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Why You Should  Charge Your Friends Why You Should  Charge Your Friends

Why You Should Charge Your Friends - PowerPoint Presentation

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Why You Should Charge Your Friends - PPT Presentation

for Borrowing Your Stuff Kijung Shin Euiwoong Lee Dhivya Eswaran Ariel Procaccia Carnegie Mellon University In Partial Fulfillment of the Speaking Requirement Sharable Goods Question ID: 669119

borrowing friends kijung stuff friends borrowing stuff kijung shin charge social sgg strategy underprivileged game access player defect cost

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Slide1

Why You Should Charge Your Friends for Borrowing Your Stuff

Kijung Shin, Euiwoong Lee, Dhivya Eswaran, Ariel ProcacciaCarnegie Mellon University

In Partial Fulfillment of the Speaking RequirementSlide2

Sharable Goods: QuestionWhy You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)2/73

“What do they have in common?”

portable crib

IKEA toolkit

DVDsSlide3

Sharable Goods: PropertiesUsed occasionallyLend to friendsDo not lend to strangersWhy You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)

3/73Slide4

Social Network: Question

Consider a social network, which is a graphNodes: peopleEdges: friendshipWhy You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)

4/73

Alice

Carol

Bob

“How many people should buy an

IKEA

toolkit for everyone to use

it

?”Slide5

Social Optimal Decision

The answer is at least peopleSocially optimal: with minimum purchases (or with minimum cost) everyone uses a toolkit Why You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)

5/73

Bob

“Does everyone want to stick to

their current decisions?”

AliceSlide6

Individually Optimal DecisionThe answer is NoIndividually optimal: everyone best responses to others’ decisions

Socially inefficient (suboptimal): 4 purchases happen when 2 are enoughWhy You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)6/73

Alice

BobSlide7

Social InefficiencyIndividually optimal outcome with 6 purchases

Why You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)7/73

Dan

Carol

“How can we prevent this social inefficiency?”Slide8

Moving toward Social OptimumWhy You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)

8/73“How can we make people to stick with this socially optimal outcome?”

Recall the

socially optimal outcome

Bob

AliceSlide9

Imposing Access Costs

Renters pay a

cost

for getting

permanent

accessAccess cost is half the price of a toolkit

Why You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)

9

/73

“Does everyone want to stick to

their current decisions?”

Bob

AliceSlide10

Socially & Individually Optimal

The answer is

Yes

Alice & Bob:

are

paid more than the priceThe others: renting is cheaper than buying

Individually optimal

Socially optimal

with minimum (2) purchases

Why You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)

10

/73

Bob

AliceSlide11

Goal and ApproachesGoal: To examine incentives to buy sharable goodsApproaches:

game-theoretic models with equilibrium analysis and simulationsQuestions: Q1. How socially inefficient are individually optimal outcomes?Q2. Do access costs reduce the social inefficiency?Q3. What is the proper access cost?Why You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)11/73

Sharable good game (SGG)

Sharable good game

with access cost (SGG-AC)Slide12

Road Map

Why You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)12/73

Concepts in Game Theory

Game-theoretic Models

Sharable Good Game

Sharable Good Game with Access Cost

Simulation

ConclusionSlide13

Road MapWhy You Should Charge Your Friends for Borrowing Your Stuff (by

Kijung Shin)13/73

Concepts in Game Theory <<

Game-theoretic Models

Sharable Good Game

Sharable Good Game with Access Cost

Simulation

ConclusionSlide14

Concept: GameA normal-form game consists of

Players : entities who make decisionsStrategy set : possible strategies that each player can takeOutcome: a vector of strategies

where

is the strategy of player

Utility

of each player at each outcome

: utility of player

: utility of player

at outcome

 

Why You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)

14

/73Slide15

Example: Prisoner’s DilemmaPlayers: two men who are charged with a crimeStrategy set: {cooperate, defect}cooperate: stay silent

defect: talk to the police and admit their crimeUtility:both cooperate: both will be jailed for 1 yearboth defect: both will be jailed for 6 yearsone defects and the other cooperates: one who defects will be freed while the other will be jailed for 9 yearsWhy You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)

15/73Slide16

Example: Prisoner’s DilemmaWhy You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)

16/73-1, -1-9, 0

0,

-9

-6

,

-6

Cooperate

Defect

Cooperate

Defect

Player 2’s strategy

Player 1’s strategy

Utility of

Player 1

Utility of

Player 2Slide17

Concept: Nash EquilibriumNash Equilibrium (NE): is an outcome

where each player’s strategy is a best response when fixing the other players’ strategies

Formally, in an NE

, for each player

,

 

Why You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)

17

/73

 

current strategy of player

 

other players’ current strategies (FIXED)

possible strategy

of player

 Slide18

Utility of Player 1Utility of Player 2

Example: Nash EquilibriumClaim: (Defect, Defect) is an NE in Prisoner’s DilemmaWhy You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)18/73

-1, -1

-9, 0

0, -9

-6, -6

Cooperate

Defect

Cooperate

Defect

Player 2’s Strategy

Player 1’s StrategySlide19

-1, -1

-9, 00, -9-6,

-6Cooperate

Defect

Cooperate

Defect

Example: Nash Equilibrium

Claim:

(Defect, Defect)

is an NE in Prisoner’s Dilemma

Why You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)

19

/73

if Player 1 changes its strategy

Player 2’s Strategy

Player 1’s StrategySlide20

-1, -1

-9, 0-6, -6Example: Nash EquilibriumClaim: (Defect, Defect) is an NE in Prisoner’s Dilemma

Why You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)

20/73

0,

-9

Cooperate

Defect

Cooperate

Defect

if Player2 changes its strategy

Player 2’s Strategy

Player 1’s StrategySlide21

Example: Nash EquilibriumClaim: (Defect, Defect) is an NE in Prisoner’s Dilemma

Why You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)21/73-1, -1-9, 0

0, -9

-6, -6

Cooperate

Defect

Cooperate

Defect

Player 2’s Strategy

Player 1’s StrategySlide22

Example: Nash EquilibriumClaim: (Cooperate, Cooperate) is not an NE

Why You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)22/73-1, -1-9, 0

0, -9

-6, -6

Cooperate

Defect

Cooperate

Defect

Player 2’s Strategy

Player 1’s StrategySlide23

Example: Nash EquilibriumClaim: (Cooperate, Cooperate) is not an NE

Why You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)23/73-1, -1

-9, 0

0, -9

-6, -6

Cooperate

Defect

Cooperate

Defect

-9

,

0

if Player 2 changes its strategy

Player 2’s Strategy

Player 1’s StrategySlide24

Concept: Social OptimumSocial welfare in an outcomesum of utilities of all players in the outcomeSocial optimum

: an outcome where social welfare is maximizedGenerally, Why You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)24/73social optimum Nash equilibrium

 Slide25

Example: Social OptimumClaim: (Cooperate, Cooperate) is a social optimum

Why You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)25/73-1 + -1= -2-9 + 0

= -9

0 -9

= -9

-6 -6

= -12

Cooperate

Defect

Cooperate

Defect

Player 2’s Strategy

Player 1’s StrategySlide26

Example: Social OptimumNash equilibrium

social optimum Why You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)26/73-1, -2

-9, 0

0, -9

-6, -6

Cooperate

Defect

Cooperate

Defect

Player 2’s Strategy

Player 1’s Strategy

Social

optimum

Nash equilibriumSlide27

Game Theory Concepts: SummaryNash equilibrium: an outcome where each user best responds to others’ strategiesSocial welfare: sum of utilities of all players

Social optimum: an outcome where the social welfare is maximizedWhy You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)27/73Slide28

Road Map

Why You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)28/73

Concepts in Game Theory

Game-theoretic Models

Sharable Good Game <<

Sharable Good Game with Access Cost

Simulation

ConclusionSlide29

Sharable Good Game (SGG)Consider a good sharable with friendsPlayers: nodes in a social networkStrategy set: buy a good ( ) or not buy ( )

Utility:owner: (benefit) – (price) ()free rider: (benefit) underprivileged:  Why You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)

29/73

)

owner

underprivileged

free rider (friends of the owner)Slide30

Nash Equilibrium: Conditionsno underprivileged nodesunderprivileged nodes become owners by changing their strategy to “buy”

owners have no owner friends otherwise, owners become free riders by changing their strategy to “not buy”Why You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)30/73Utility comparison:free rider > owner > underprivileged

underprivileged

owner

owner

free riderSlide31

Nash Equilibrium: ExistenceProof: The following algorithm always gives an NEWhy You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)31

/73Theorem [Existence of NEs in SGG]:In any social network, there exists a Nash Equilibrium.initialize the strategy of every node to “not buy” repeat until there is no underprivileged nodechoose an underprivileged node

change its strategy to “buy”

“Do Nash equilibria exist

in every social network?”Slide32

Proof of ExistenceWhy You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)32/73

initialize the strategy of every node to “not buy” repeat until there is no underprivileged nodechoose an underprivileged node change its strategy to “buy”

Underprivileged

DetailSlide33

Proof of Existence (cont.)Why You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)33/73

Underprivileged

initialize the strategy of every node to “not buy”

repeat

until there is no underprivileged node

choose an underprivileged node

change its strategy to “buy”

DetailSlide34

Proof of Existence (cont.)Why You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)34/73

Free riders

Underprivileged

initialize the strategy of every node to “not buy”

repeat

until there is no underprivileged node

choose an underprivileged node

change its strategy to “buy”

Detail

UnderprivilegedSlide35

Proof of Existence (cont.)Why You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)35/73

initialize the strategy of every node to “not buy” repeat until there is no underprivileged nodechoose an underprivileged node change its strategy to “buy”

Free riders

Underprivileged

Detail

Underprivileged

UnderprivilegedSlide36

Proof of Existence (cont.)Why You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)

36/73The outcome is a Nash Equilibriumno underprivileged nodesthis is the termination conditionowners have no owner friends new owners are chosen among underprivileged nodesinitialize the strategy of every node to “not buy” repeat until there is no underprivileged node

choose an underprivileged node change its strategy to “buy”

DetailSlide37

Nash Equilibrium: Non-uniquenessWhy You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)

37/73“Is there a unique Nash equilibriumin every social network?”Slide38

Nash Equilibrium: Non-uniquenessWhy You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)

38/73Theorem [Non-uniqueness of NEs in SGG]:There can be multiple Nash equilibria with different social welfareExample:

NE with social welfare

 

NE with social welfare

 

Social OptimumSlide39

Measuring InefficiencyIn every NE and social optima

no underprivileged nodeevery node gets benefit from a goodUse # owners to measure inefficiency of NEsWhy You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)

39/73

 

benefit

# nodes

price

# owners

Fixed

FixedSlide40

Measuring Inefficiency (cont.)Given a social network,Given a social network,Why You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)

40/73# owners in a social optimum# owners in the NEinefficiency of an NE

:= PoA

(Price of Anarchy)

maximum inefficiency

over all NEs

PoS

(Price of Stability)

:=

minimum

inefficiency

over all NEs

:=

 Slide41

Worst-case AnalysisWhy You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)41/73

Example :…

 

 

Theorem

[Worst-case Analysis in SGG]

:

There exists a social network with

nodes

where

both

PoA

and

PoS

are

 Slide42

Worst-case Analysis (cont.)Why You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)42/73

Theorem [Worst-case Analysis in SGG]:There exists a social network with nodes where both PoA and PoS are

 

Example :

social optimum

(

owners)

 

least efficient NE

(

owners)

 

most efficient NE

(

owners)

 

 

 Slide43

Reason of InefficiencyA Nash equilibrium is inefficient whennodes with many friends free ridenodes with few friends buy a goodWhy You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)

43/73…

social optimum

(

owners)

 

most efficient NE

(

owners)

 

least efficient NE

(

owners)

 

“How can we incentivize nodes

with many friends to buy a good?”Slide44

Summary of SGGDefinition:Players: nodes in a social networkStrategy set: “buy”, “not buy”

Utility: free rider > owner > underprivilegedNash Equilibrium: always exists but not uniqueEfficiency of Nash Equilibria:both best and worst NEs can be highly inefficientWhy You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)44/73Slide45

Road MapWhy You Should Charge Your Friends for Borrowing Your Stuff (by

Kijung Shin)45/73

Concepts in Game Theory

Game-theoretic Models

Sharable Good Game

Sharable Good Game with Access Cost <<

Simulation

ConclusionSlide46

SGG with Access Cost (SGG-AC)Consider a good sharable with friendsPlayers: nodes in a social networkStrategy set: buy a good ( ) or not buy ( )

rent a good from a friend by paying an access cost ( ) to the friendWhy You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)46/73

)

owner

renter

renter

underprivilegedSlide47

Utility in SGG-ACUtility: owner: (benefit)

(price) (access cost) (# its renters)renter: (benefit) (access cost)underprivileged: (assumption:

)Rich owner and poor owner:rich owner: owner with at least

renters

poor owner

: owner with less than

renter

 

Why You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)

47

/73

owner

renter

renter

underprivileged

Utility comparison:

rich owner > renter > poor owner > underprivilegedSlide48

Nash Equilibrium: ConditionsWhy You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)

48/73

no

underprivileged

nodes

underprivileged nodes become owners by changing their strategy to “buy”

poor owners have no owner friends

otherwise, poor owners become renters by changing their strategy to “rent”

underprivileged

Utility comparison:

rich owner > renter > poor owner > underprivileged

poor owner

poor owner

renterSlide49

Existence and Non-uniquenessWhy You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)49/73

Theorem [Existence of NEs in SGG-AC]:In any social network, there exists a Nash Equilibrium.Theorem [Non-uniqueness of NEs in SGG]:There can be multiple Nash equilibria with different social welfare

NE with

5 owners

NE with

1 owner

Example :Slide50

Measuring Inefficiency: ReviewGiven a social network,Given a social network,Why You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)

50/73# owners in a social optimum# owners in the NEinefficiency of an NE

:=

PoA

(Price of Anarchy)

maximum

inefficiency over all NEs

PoS

(Price of Stability)

:=

minimum

inefficiency

over all NEs

:=

 Slide51

Worst-case Analysis: PoAWhy You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)

51/73Theorem [Worst-case PoA Analysis in SGG-AC]:There exists a social network with nodes where PoA is

 

Example :

 

 

Worst

NEs

in SGG-AC are as

inefficient

as those in SGGSlide52

Worst-case Analysis: PoAWhy You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)

52/73social optimum( owners) 

least efficient NE

(

owners)

 

 

Theorem

[Worst-case

PoA

Analysis in SGG-AC]

:

There exists a social network with

nodes

where

PoA

is

 Slide53

Worst-case Analysis: PoSWhy You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)

53/73Theorem [Worst-case PoS Analysis in SGG-AC]:If (i.e.,

), then

PoS is

in every network.

 

If

,

b

est

NEs

are

socially optimal.

 

Proof Sketch:

w

e designed an algorithm that

starts from a social optimum

reaches a Nash equilibrium

without increasing the number of ownersSlide54

Worst-case Analysis: PoSWhy You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)

54/73Theorem [Worst-case PoS Analysis in SGG-AC]:If (i.e.,

), then

PoS is

in every network.

 

social optimum,

Nash equilibrium

Example

:

 

 

 Slide55

Worst-case Analysis: PoSWhy You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)

55/73Theorem [Worst-case PoS Analysis in SGG-AC]:If PoS

is in every social network.

If

,

PoS

is

in every social network

There exists a social network where

PoS

is

 

Detail

(i.e., the number of nodes)

PoS

in SGG-AC

PoS

in SGG with

 Slide56

Worst-case Analysis: PoSWhy You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)

56/73DetailTheorem [Worst-case

PoS Analysis in SGG-AC]:If

PoS

is

in every social network.

If

,

PoS

is

in every social network

There exists a social network where

PoS

is

 

 

 

Example

:Slide57

Worst-case Analysis: PoSWhy You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)

57/73Theorem [Worst-case PoS Analysis in SGG-AC]:If PoS

is in every social network.

If

,

PoS

is

in every social network

There exists a social network where

PoS

is

 

Detail

social optimum

(

owners)

 

most efficient NE

(T owners)

 Slide58

Summary of Theoretic AnalysisWhy You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)

58/73PoAPoSSGG

SGG-AC

if

otherwise

PoA

PoS

SGG

SGG-AC

Introducing access costs

(SGG

SGG-AC)

:

Does not reduce inefficiency of worst NEs:

Does reduce inefficiency of best NEs:

or

 

“How inefficient are other NEs,

which are neither best nor worst?”Slide59

Summary of SGG-ACDefinition:Players: nodes in a social network

Strategy set: “buy”, “rent with an access cost”, “no buy no rent”Utility: rich owner > renter > poor owner > underprivilegedNash Equilibrium: always exists but not uniqueEfficiency of Nash Equilibria:best NEs are always efficient (socially optimal if )worst NEs can be highly inefficient 

Why You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)

59

/73Slide60

Road MapWhy You Should Charge Your Friends for Borrowing Your Stuff (by

Kijung Shin)60/73

Concepts in Game Theory

Game-theoretic Models

Sharable Good Game

Sharable Good Game with Access Cost

Simulation <<

ConclusionSlide61

Why Simulation?Complement our theoretical analysisReal social networks:Karate club (34 nodes, 78 edges)Hamsterster (1,858 nodes, 12,534 edges)Advogato (5,155 nodes, 51,127 edges)

Why You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)61/73Nash EquilibriaSocial NetworkTheoretical analysis

best and worst NEshypothetical social networks

Simulation

realistic NEs

real

social networksSlide62

Simulation MethodUse best-response dynamics to obtain 1,000 NEs

Measure the average inefficiency of the 1,000 NEsWhy You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)62/73

randomly initialize strategies

repeat

for each

node

change its strategy to a

best response

until

an NE is reached

Theorem:

Always terminates

# owners in a social optimum

# owners in the NE

inefficiency

of an NE

:=Slide63

Simulation ResultsAverage (social) inefficiencyWhy You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)

63/73GamesSGG

SGG-AC

Access cost

1

2

5

10

Karate Club

Hamsterster

Advogato

Games

SGG

SGG-AC

Access cost

1

2

5

10

Karate Club

Hamsterster

AdvogatoSlide64

Simulation Results: SGGAverage social inefficiencyWhy You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)

64/73SGG

SGG-AC

Access cost

1

2

5

10

Karate Club

Hamsterster

Advogato

SGG

SGG-AC

Access cost

1

2

5

10

Karate Club

Hamsterster

Advogato

- In SGG (without access cost), inefficiency was

 Slide65

Simulation Results: SGG-ACAverage social inefficiencyWhy You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)

65/73SGG

SGG-AC

Access cost

1

2

5

10

Karate Club

Hamsterster

Advogato

SGG

SGG-AC

Access cost

1

2

5

10

Karate Club

Hamsterster

Advogato

- In SGG (without access cost), inefficiency was

- In SGG-AC with a proper access cost, inefficiency was

 Slide66

Simulation Results: Proper CostAverage social inefficiencyWhy You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)

66/73SGG

SGG-AC

Access cost

1

2

5

10

Karate Club

Hamsterster

Advogato

SGG

SGG-AC

Access cost

1

2

5

10

Karate Club

Hamsterster

Advogato

Inefficiency was minimized when

(i.e.,

)

 

Theorem

PoS

is minimized when

 Slide67

Summary of SimulationComplements our theoretical analysisanalyze realistic Nash Equilibriause real social networks

Supports our theoretical analysisinefficiency decreases by access costs: inefficiency is minimized when (i.e.,

)

 

Why You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)

67

/73Slide68

Road MapWhy You Should Charge Your Friends for Borrowing Your Stuff (by

Kijung Shin)68/73

Concepts in Game Theory

Game-theoretic Models

Sharable Good Game

Sharable Good Game with Access Cost

Simulation

Conclusion <<Slide69

SummaryGoal: To examine incentives to buy sharable goodsApproaches:

game-theoretic models with equilibrium analysis and simulationsFindings: individually optimal purchases can be harmful to societyaccess costs significantly reduce social inefficiencyproper access cost lies between 1/3 and 1/2 of the priceWhy You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)69/73

Sharable good game (SGG)

Sharable good game

with access cost (SGG-AC)Slide70

Actionable ConclusionHard to mandate access costs at a societal level IKEA toolkits, DVDs, etc.Feasible at the level of an organization Example: University researchers share expensive lab equipment

mandating access costs might reduce costWhy You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)70/73Slide71

Future Work: CoalitionTake coalitions of nodes into accountAnalyze coalition-proof equilibriaE.g., “strong Nash equilibria”

Why You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)71/73Slide72

Related WorkShin et al [2017] – the full paperconsider goods sharable with nodes within distance

Bramoulle and Kranton [2007]strategy is the amount of contribution to a public goodElliott and Golub [2013]consider directed and weighted graphsAllouch [2015]consider both private goods and public goods Jackson and Zenou [2014]survey on games on networks Why You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)

72/73Slide73

Thank YouPaper: http://www.cs.cmu.edu/~kijungs/papers/sggIJCAI2017.pdfEmail: kijungs@cs.cmu.edu

Why You Should Charge Your Friends for Borrowing Your Stuff (by Kijung Shin)73/73