SLIDE 1 Design of Information Sharing Mechanisms
Krishnamurthy Iyer
ORIE, Cornell University Oct 2018, IMA Based on joint work with David Lingenbrink, Cornell University
SLIDE 2 Motivation
Many instances in the service economy where users’ payoff from using the service depends on the state of the system.
- congestion, resource availability, waiting times, etc.
SLIDE 3 Motivation
Many instances in the service economy where users’ payoff from using the service depends on the state of the system.
- congestion, resource availability, waiting times, etc.
Typically, such system states are unknown to the user, but the system operator is better informed.
SLIDE 4 Motivation
Many instances in the service economy where users’ payoff from using the service depends on the state of the system.
- congestion, resource availability, waiting times, etc.
Typically, such system states are unknown to the user, but the system operator is better informed. Due to this informational asymmetry, the system operator may share information with its users.
SLIDE 5 Motivation
Many instances in the service economy where users’ payoff from using the service depends on the state of the system.
- congestion, resource availability, waiting times, etc.
Typically, such system states are unknown to the user, but the system operator is better informed. Due to this informational asymmetry, the system operator may share information with its users. Information design: How should an operator share information with potential users to influence their behavior?
SLIDE 6
Motivation: Uber vs. taxi
Suppose you land at the MSP airport. You don’t want to wait too long for a ride to your destination, so you decide between using Uber or a taxi service.
SLIDE 7 Motivation: Uber vs. taxi
Suppose you land at the MSP airport. You don’t want to wait too long for a ride to your destination, so you decide between using Uber or a taxi service.
- Taxi rides cost more, but are readily available.
SLIDE 8 Motivation: Uber vs. taxi
Suppose you land at the MSP airport. You don’t want to wait too long for a ride to your destination, so you decide between using Uber or a taxi service.
- Taxi rides cost more, but are readily available.
- Uber rides cost less, but you have to wait till a driver is
available.
SLIDE 9 Motivation: Uber vs. taxi
Suppose you land at the MSP airport. You don’t want to wait too long for a ride to your destination, so you decide between using Uber or a taxi service.
- Taxi rides cost more, but are readily available.
- Uber rides cost less, but you have to wait till a driver is
available. Before you make your choice, Uber provides estimates of your waiting time.
SLIDE 10 Motivation: Uber vs. taxi
Suppose you land at the MSP airport. You don’t want to wait too long for a ride to your destination, so you decide between using Uber or a taxi service.
- Taxi rides cost more, but are readily available.
- Uber rides cost less, but you have to wait till a driver is
available. Before you make your choice, Uber provides estimates of your waiting time. Uber’s Problem What information can Uber share with you to convince you to wait for a ride?
SLIDE 11
Motivation: Uber vs. taxi
Uber’s Problem What information can Uber share with you to convince you to wait for a ride? Ideas:
SLIDE 12 Motivation: Uber vs. taxi
Uber’s Problem What information can Uber share with you to convince you to wait for a ride? Ideas:
- Fully reveal: Customers will only join when wait is short.
SLIDE 13 Motivation: Uber vs. taxi
Uber’s Problem What information can Uber share with you to convince you to wait for a ride? Ideas:
- Fully reveal: Customers will only join when wait is short.
- Tell nothing: Customers will join with some fixed probability.
SLIDE 14 Motivation: Uber vs. taxi
Uber’s Problem What information can Uber share with you to convince you to wait for a ride? Ideas:
- Fully reveal: Customers will only join when wait is short.
- Tell nothing: Customers will join with some fixed probability.
- Partial information?
SLIDE 15 Motivation: Uber vs. taxi
Uber’s Problem What information can Uber share with you to convince you to wait for a ride? Ideas:
- Fully reveal: Customers will only join when wait is short.
- Tell nothing: Customers will join with some fixed probability.
- Partial information?
In this talk How can a service provider disclose information to increase participation in a queue, thereby increasing revenue?
SLIDE 16 Literature review
Bayesian persuasion: Optimal information sharing between principal and a set of uninformed agents.
- Rayo and Segal [2010], Kamenica and Gentzkow [2011]
- Mansour et al. [2015], Bergemann and Morris [2017], Dughmi
and Xu [2016], Papanastasiou et al. [2017]
SLIDE 17 Literature review
Bayesian persuasion: Optimal information sharing between principal and a set of uninformed agents.
- Rayo and Segal [2010], Kamenica and Gentzkow [2011]
- Mansour et al. [2015], Bergemann and Morris [2017], Dughmi
and Xu [2016], Papanastasiou et al. [2017] Strategic behavior in queues: Naor [1969], Edelson and Hilderbrand [1975], Chen and Frank [2001], Hassin et al. [2003], Hassin [2016]
- Allon et al. [2011] study cheap talk in unobservable queues for
more general objectives for service provider.
- Simhon et al. [2016], Guo and Zipkin [2007]: specific types of
information.
SLIDE 18
Model
SLIDE 19
Model: Queue
Customers arrive according to a Poisson process with rate λ. The queue is unobservable to arriving customers who must choose whether to join the queue upon arrival.
SLIDE 20 Model: Queue
Customers arrive according to a Poisson process with rate λ. The queue is unobservable to arriving customers who must choose whether to join the queue upon arrival. Joining customers pay price p ≥ 0 and wait in a FIFO queue to
- btain service from a single server.
Service time is exponentially distributed with mean 1.
SLIDE 21
Model: Customers
Customers are homogeneous, delay sensitive, and Bayesian.
SLIDE 22
Model: Customers
Customers are homogeneous, delay sensitive, and Bayesian. Customers who do not join the queue receive zero utility.
SLIDE 23 Model: Customers
Customers are homogeneous, delay sensitive, and Bayesian. Customers who do not join the queue receive zero utility. When the queue has length X, joining customers have expected utility h(X, p) = u(X) − p,
- u(X) is the expected utility the customer gets from the service,
- p is the fixed price for the service.
SLIDE 24 Model: Assumptions
1 2 3 4 5 6 7 8
x
0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
u(x) Customers ...
u(·) non-increasing.
- ...would join an empty queue.
u(0) − p ≥ 0
- ...would not join long queues.
∃ Mp s.t. u(Mp) − p < 0.
SLIDE 25 Model: Customers
Customers are homogeneous, delay sensitive, and Bayesian. Customers who do not join the queue receive zero utility. When the queue has length X, joining customers have expected utility h(X, p) = u(X) − p,
- u(X) is the expected utility the customer gets from the service,
- p is the fixed price for the service.
SLIDE 26 Model: Customers
Customers are homogeneous, delay sensitive, and Bayesian. Customers who do not join the queue receive zero utility. When the queue has length X, joining customers have expected utility h(X, p) = u(X) − p,
- u(X) is the expected utility the customer gets from the service,
- p is the fixed price for the service.
Queue length X is unknown: customers maintain beliefs, and maximize expected utility.
SLIDE 27 Model: Service provider
The service provider aims to maximize expected revenue by choosing
SLIDE 28 Model: Service provider
The service provider aims to maximize expected revenue by choosing
- a fixed price p,
- a signaling mechanism.
SLIDE 29 Model: Signaling mechanism
Formally, a signaling mechanism is
- a set of possible signals S and
SLIDE 30 Model: Signaling mechanism
Formally, a signaling mechanism is
- a set of possible signals S and
- a mapping from queue lengths to distributions over S, σ:
σ(n, s) = P(signal s | queue length = n).
SLIDE 31 Model: Signaling mechanism
Formally, a signaling mechanism is
- a set of possible signals S and
- a mapping from queue lengths to distributions over S, σ:
σ(n, s) = P(signal s | queue length = n). Examples:
S = {∅}, σ(n, ∅) = 1
SLIDE 32 Model: Signaling mechanism
Formally, a signaling mechanism is
- a set of possible signals S and
- a mapping from queue lengths to distributions over S, σ:
σ(n, s) = P(signal s | queue length = n). Examples:
S = {∅}, σ(n, ∅) = 1
S = N0, σ(n, n) = 1,
SLIDE 33 Model: Signaling mechanism
Formally, a signaling mechanism is
- a set of possible signals S and
- a mapping from queue lengths to distributions over S, σ:
σ(n, s) = P(signal s | queue length = n). Examples:
S = {∅}, σ(n, ∅) = 1
S = N0, σ(n, n) = 1,
S = N0 ∪ {∅}, σ(n, n) = σ(n, ∅) = 1
2.
SLIDE 34
Equilibrium
SLIDE 35 Equilibrium
Each signaling mechanism induces an equilibrium among the customers:
- 1. Optimality: Given her prior belief (about queue state) and
- ther customers’ strategies, each customer acts optimally.
- 2. Consistency: A customer’s prior belief is consistent with the
queue dynamics induced by the strategies.
SLIDE 36 Equilibrium
Each signaling mechanism induces an equilibrium among the customers:
- 1. Optimality: Given her prior belief (about queue state) and
- ther customers’ strategies, each customer acts optimally.
- 2. Consistency: A customer’s prior belief is consistent with the
queue dynamics induced by the strategies. Bayesian Persuasion in Dynamic Setting The choice of the signaling mechanism affects not only what information a customer receives, but also her prior belief.
SLIDE 37
Dynamics
A customer strategy is a function f : S → [0, 1] such that given a signal s, a customer joins with probability f(s).
SLIDE 38 Dynamics
A customer strategy is a function f : S → [0, 1] such that given a signal s, a customer joins with probability f(s). qn: probability a customer joins given there are n customers, qn =
σ(n, s)f(s)
SLIDE 39 Dynamics
A customer strategy is a function f : S → [0, 1] such that given a signal s, a customer joins with probability f(s). qn: probability a customer joins given there are n customers, qn =
σ(n, s)f(s) 1 2 . . . n n+1 . . . λq0 λq1 λqn 1 1 1 The queue forms a birth-death chain.
SLIDE 40 Dynamics
A customer strategy is a function f : S → [0, 1] such that given a signal s, a customer joins with probability f(s). qn: probability a customer joins given there are n customers, qn =
σ(n, s)f(s) 1 2 . . . n n+1 . . . λq0 λq1 λqn 1 1 1 The queue forms a birth-death chain. Let π denote its steady state distribution and X∞ ∼ π.
SLIDE 41 Customer equilibrium
A symmetric equilibrium among customers is a strategy f that maximizes a customer’s expected utility (under steady state) assuming all other customers follow f: f(s) =
if E[h(X∞, p)|s] > 0; if E[h(X∞, p)|s] < 0.
SLIDE 42 Service provider’s goal
The service provider’s revenue is given by R(σ, f, p) = p · 1 · (1 − π0) = p
∞
πi.
SLIDE 43 Service provider’s goal
The service provider’s revenue is given by R(σ, f, p) = p · 1 · (1 − π0) = p
∞
πi.
1 2 3 4 5 λ 0.00 0.05 0.10 0.15 0.20 0.25 0.30 Revenue
Full No-Info
(a) c = 0.2 and p = 0.3.
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 c 0.00 0.05 0.10 0.15 0.20 0.25 Revenue
Full No-Info
(b) λ = 0.7 and p = 0.3.
u(X) = 1 − c · (X + 1)
SLIDE 44 Service provider’s goal
The service provider’s revenue is given by R(σ, f, p) = p · 1 · (1 − π0) = p
∞
πi. Problem: Optimal Signaling and Pricing How should a service provider choose a price p and a signaling mechanism (S, σ) to maximize her expected revenue R(σ, f, p) in the resulting equilibrium?
SLIDE 45
Signaling under Fixed Price
SLIDE 46
Characterizing the optimal mechanism
Lemma It suffices to consider signaling mechanisms (S, σ) where S = {0, 1} and the customer equilibrium f is obedient: f(s) = s.
SLIDE 47
Characterizing the optimal mechanism
Lemma It suffices to consider signaling mechanisms (S, σ) where S = {0, 1} and the customer equilibrium f is obedient: f(s) = s. Proof: Standard revelation principle argument.
SLIDE 48
Optimal signaling mechanism
Theorem For any fixed-price p > 0, there exists an optimal signaling mechanism with a threshold structure.
SLIDE 49
Optimal signaling mechanism
Theorem For any fixed-price p > 0, there exists an optimal signaling mechanism with a threshold structure. Threshold mechanism: · · ·
join leave
N ∗
(randomize)
1 2 3
SLIDE 50
Optimal signaling mechanism
Theorem For any fixed-price p > 0, there exists an optimal signaling mechanism with a threshold structure. Threshold mechanism: · · ·
join leave
N ∗
(randomize)
1 2 3 Here, N ∗ ≥ Mp (max queue size under full information).
SLIDE 51
Intuition
Suppose the signaling mechanism fully revealed the queue length X: · · · Mp 1 2 3
SLIDE 52
Intuition
Suppose the signaling mechanism fully revealed the queue length X: · · ·
join
Mp 1 2 3
SLIDE 53
Intuition
Suppose the signaling mechanism fully revealed the queue length X: · · ·
join
Mp 1 2 3 Joining a queue at state k < Mp gets utility u(k) − p ≥ 0.
SLIDE 54
Intuition
Suppose the signaling mechanism fully revealed the queue length X: · · ·
join
Mp 1 2 3 Joining a queue at state k < Mp gets utility u(k) − p ≥ 0. Joining a queue at state Mp gets u(Mp) − p < 0.
SLIDE 55
Intuition
Instead, suppose the signaling mechanism only revealed whether the queue length satisfies X ≤ Mp or not. · · ·
X ≤ Mp
Mp 1 2 3
SLIDE 56
Intuition
Instead, suppose the signaling mechanism only revealed whether the queue length satisfies X ≤ Mp or not. · · ·
X ≤ Mp
Mp 1 2 3 Upon receiving the signal X ≤ Mp, the utility for joining is a convex combination of u(k) for k ≤ Mp.
SLIDE 57
Intuition
Instead, suppose the signaling mechanism only revealed whether the queue length satisfies X ≤ Mp or not. · · ·
X ≤ Mp
Mp 1 2 3 Upon receiving the signal X ≤ Mp, the utility for joining is a convex combination of u(k) for k ≤ Mp. If positive, then customer will join, even if the queue length is Mp!
SLIDE 58 Proof sketch
max
σ
Eσ [R(σ, f, p)] s.t., Eσ[h(X∞, p)|s = 1] ≥ 0, Eσ[h(X∞, p)|s = 0] ≤ 0
SLIDE 59 Proof sketch
max
σ
Eσ [R(σ, f, p)] s.t., Eσ[h(X∞, p)|s = 1] ≥ 0, Eσ[h(X∞, p)|s = 0] ≤ 0 We can write the expectations in terms of π, the stationary distribution.
SLIDE 60 Proof sketch
max
σ
Eσ [R(σ, f, p)] s.t., Eσ[h(X∞, p)|s = 1] ≥ 0, Eσ[h(X∞, p)|s = 0] ≤ 0 max
σ ∞
πn s.t.,
∞
h(n − 1, p)πn ≥ 0
∞
h(n, p) (λπn − πn+1) ≤ 0 λπn − πn+1 ≥ 0 πT1 = 1, π ≥ 0 ∀n We can write the expectations in terms of π, the stationary distribution.
SLIDE 61 Proof sketch
max
σ ∞
πn s.t.,
∞
h(n − 1, p)πn ≥ 0
∞
h(n, p) (λπn − πn+1) ≤ 0 λπn − πn+1 ≥ 0 πT1 = 1, π ≥ 0 ∀n
SLIDE 62 Proof sketch
max
σ ∞
πn s.t.,
∞
h(n − 1, p)πn ≥ 0
∞
h(n, p) (λπn − πn+1) ≤ 0 λπn − πn+1 ≥ 0 πT1 = 1, π ≥ 0 ∀n Instead of optimizing over the signaling mechanism, we can
- ptimize over the stationary distribution π.
SLIDE 63 Proof sketch
max
π ∞
πn s.t.,
∞
h(n − 1, p)πn ≥ 0
∞
h(n, p) (λπn − πn+1) ≤ 0 λπn − πn+1 ≥ 0 πT1 = 1, π ≥ 0 ∀n Instead of optimizing over the signaling mechanism, we can
- ptimize over the stationary distribution π.
SLIDE 64 Proof sketch
max
π ∞
πn s.t.,
∞
h(n − 1, p)πn ≥ 0
∞
h(n, p) (λπn − πn+1) ≤ 0 λπn − πn+1 ≥ 0 πT1 = 1, π ≥ 0 ∀n We have an (infinite) LP in {πn : n ≥ 0}.
SLIDE 65 Proof sketch
max
π ∞
πn s.t.,
∞
h(n − 1, p)πn ≥ 0
∞
h(n, p) (λπn − πn+1) ≤ 0 λπn − πn+1 ≥ 0 πT1 = 1, π ≥ 0 ∀n We have an (infinite) LP in {πn : n ≥ 0}. We can perturb any feasible solution to this LP to a threshold mechanism without decreasing the revenue.
SLIDE 66 Proof sketch
max
π ∞
πn s.t.,
∞
h(n − 1, p)πn ≥ 0
∞
h(n, p) (λπn − πn+1) ≤ 0 λπn − πn+1 ≥ 0 πT1 = 1, π ≥ 0 ∀n We first show that for queue lengths less than Mp, the optimal mechanism must tell customers to join.
SLIDE 67 Proof sketch
Next, we consider an feasible solution π where πn = λnπ0 for n ≤ N, 0 < πN+1 ≤ πN < λπN−1. λn
5 10 15 0.2 0.4 0.6 0.8 1.0
SLIDE 68 Proof sketch
Next, we consider an feasible solution π where πn = λnπ0 for n ≤ N, 0 < πN+1 ≤ πN < λπN−1. λn
5 10 15 0.2 0.4 0.6 0.8 1.0
We construct a better solution by increasing πN+1 by β
n>N+1 πn
and scaling down πn by (1 − β) for n > N + 1.
SLIDE 69
Optimal signaling mechanism
Theorem For any fixed-price p > 0, there exists an optimal signaling mechanism with a threshold structure.
SLIDE 70
Optimal signaling mechanism
Theorem For any fixed-price p > 0, there exists an optimal signaling mechanism with a threshold structure. For linear waiting costs: closed-form for the threshold.
SLIDE 71 Revenue comparison
u(X) = 1 − c · (X + 1)
1 2 3 4 5 λ 0.00 0.05 0.10 0.15 0.20 0.25 0.30 Revenue
Full No-Info
(a) c = 0.2 and p = 0.3.
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 c 0.00 0.05 0.10 0.15 0.20 0.25 Revenue
Full No-Info
(b) λ = 0.7 and p = 0.3.
SLIDE 72 Revenue comparison
u(X) = 1 − c · (X + 1)
1 2 3 4 5 λ 0.00 0.05 0.10 0.15 0.20 0.25 0.30 Revenue
Optimal Full No-Info
(a) c = 0.2 and p = 0.3.
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 c 0.00 0.05 0.10 0.15 0.20 0.25 Revenue
Optimal Full No-Info
(b) λ = 0.7 and p = 0.3.
SLIDE 73
Optimal Signaling and Pricing
SLIDE 74
Optimal price
We consider the setting where we can choose the optimal fixed price, in addition to subsequent optimal signaling.
SLIDE 75 Optimal price
We consider the setting where we can choose the optimal fixed price, in addition to subsequent optimal signaling. Benchmark: Optimal state-dependent prices in a fully-observable
- queue. [Naor, 1969, Edelson and Hilderbrand, 1975, Chen and Frank,
2001].
SLIDE 76 Optimal price
We consider the setting where we can choose the optimal fixed price, in addition to subsequent optimal signaling. Benchmark: Optimal state-dependent prices in a fully-observable
- queue. [Naor, 1969, Edelson and Hilderbrand, 1975, Chen and Frank,
2001]. Here, the service provider sets prices p(n) for each queue length n:
- a cutoff k such that p(n) = ∞, for n ≥ k.
SLIDE 77 Optimal price
We consider the setting where we can choose the optimal fixed price, in addition to subsequent optimal signaling. Benchmark: Optimal state-dependent prices in a fully-observable
- queue. [Naor, 1969, Edelson and Hilderbrand, 1975, Chen and Frank,
2001]. Here, the service provider sets prices p(n) for each queue length n:
- a cutoff k such that p(n) = ∞, for n ≥ k.
- For n < k, extract entire customer surplus: p(n) = u(n).
SLIDE 78 Optimal price
We consider the setting where we can choose the optimal fixed price, in addition to subsequent optimal signaling. Benchmark: Optimal state-dependent prices in a fully-observable
- queue. [Naor, 1969, Edelson and Hilderbrand, 1975, Chen and Frank,
2001]. Here, the service provider sets prices p(n) for each queue length n:
- a cutoff k such that p(n) = ∞, for n ≥ k.
- For n < k, extract entire customer surplus: p(n) = u(n).
Question How does our revenue compare with that of the optimal state-dependent pricing mechanism?
SLIDE 79
Optimal revenue
Theorem Revenue under optimal signaling = Revenue under optimal state dependent prices.
SLIDE 80
Optimal revenue
Theorem Revenue under optimal signaling = Revenue under optimal state dependent prices. Proof: Under optimal state-dependent prices, the expected revenue is E [I{X∞ < k}u(X∞)] .
SLIDE 81
Optimal revenue
Theorem Revenue under optimal signaling = Revenue under optimal state dependent prices. Proof: Under optimal state-dependent prices, the expected revenue is E [I{X∞ < k}u(X∞)] . We show that the signaling mechanism with threshold equal to cutoff k, and with fixed price p∗ = E [u(X∞)|X∞ < k] achieves the same revenue.
SLIDE 82
Optimal revenue
Theorem Revenue under optimal signaling = Revenue under optimal state dependent prices.
SLIDE 83 Optimal revenue
Theorem Revenue under optimal signaling = Revenue under optimal state dependent prices. In settings where it is infeasible to charge state-dependent prices,
- ptimal signaling can be effective in raising revenue.
SLIDE 84
Extensions
SLIDE 85
Extensions
State-dependent service/arrival rates
SLIDE 86
Extensions
State-dependent service/arrival rates Other service disciplines
SLIDE 87
Extensions
State-dependent service/arrival rates Other service disciplines Exogeneous abandonment
SLIDE 88 Extensions
State-dependent service/arrival rates Other service disciplines Exogeneous abandonment Rational abandonment
- Threshold mechanisms do as well; unknown whether optimal.
SLIDE 89
Heterogeneous customers
Suppose customers come from one of K types. Type i customers arrive at rate λi, are charged pi, and have utility hi(n, pi) = ui(n) − pi.
SLIDE 90
Heterogeneous customers
Suppose customers come from one of K types. Type i customers arrive at rate λi, are charged pi, and have utility hi(n, pi) = ui(n) − pi. Theorem If all customers types pay the same price, there exists an optimal signaling mechanism with a threshold structure.
SLIDE 91
Heterogeneous customers
Suppose customers come from one of K types. Type i customers arrive at rate λi, are charged pi, and have utility hi(n, pi) = ui(n) − pi. Theorem If all customers types pay the same price, there exists an optimal signaling mechanism with a threshold structure. Remark: When prices are different for different types, the optimal signaling mechanism need not have threshold structure.
SLIDE 92
Heterogeneous customers
Two types: λ1 = λ2 = 1. Prices: p1 = 50, p2 = 1. u1(n) = 51 n = 0; 40 n = 1; −10000 n ≥ 2. , u2(n) = 2 n = 0; 2 n = 1; −8.5 n ≥ 2. Optimal mechanism: σ(n, 1, 1) = 1 n = 0; 1/10 n = 1; n ≥ 2. , σ(n, 2, 1) = n = 0; 1/10 n = 1; n ≥ 2.
SLIDE 93 Risk aversion
Customers ofen perceive uncertain wait-times to be longer than definite wait-times (Maister 2005).
- Variance of the waiting time plays a role in a customer’s
decision to join.
SLIDE 94 Risk aversion
Customers ofen perceive uncertain wait-times to be longer than definite wait-times (Maister 2005).
- Variance of the waiting time plays a role in a customer’s
decision to join. Mean-Variance model: Suppose customers will join only if E[T] + β ·
where T is the waiting time.
SLIDE 95 Risk aversion
Customers ofen perceive uncertain wait-times to be longer than definite wait-times (Maister 2005).
- Variance of the waiting time plays a role in a customer’s
decision to join. Mean-Variance model: Suppose customers will join only if E[T] + β ·
where T is the waiting time. Question What is the optimal signaling mechanism under the mean-variance model?
SLIDE 96
Risk aversion
Main difficulty: Revelation principle no longer holds. Cannot reduce the space of signaling mechanisms to those with binary signals.
SLIDE 97 Risk aversion
Main difficulty: Revelation principle no longer holds. Cannot reduce the space of signaling mechanisms to those with binary signals. Restricted Revelation Principle It suffices to consider signaling mechanisms where customers’
- ptimal strategy involves not joining for at most one signal, and
joining for all others.
SLIDE 98 Risk aversion
Main difficulty: Revelation principle no longer holds. Cannot reduce the space of signaling mechanisms to those with binary signals. Restricted Revelation Principle It suffices to consider signaling mechanisms where customers’
- ptimal strategy involves not joining for at most one signal, and
joining for all others. = ⇒ an iterative approach to optimize information sharing
SLIDE 99 Risk aversion
3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 Risk-aversion, β 0.88 0.89 0.90 0.91 0.92 0.93 0.94 0.95 Throughput
Optimal Threshold Sandwich
Threshold = join | leave Sandwich = risky-join | safe-join | risky-join | leave
SLIDE 100
Conclusion
SLIDE 101 Conclusion
We study Bayesian persuasion in a dynamic queueing setting.
- The optimal signaling mechanism under a fixed price has a
threshold structure.
SLIDE 102 Conclusion
We study Bayesian persuasion in a dynamic queueing setting.
- The optimal signaling mechanism under a fixed price has a
threshold structure.
- Under optimal fixed price, optimal signaling achieves the
- ptimal revenue under state-dependent prices.
SLIDE 103 Conclusion
We study Bayesian persuasion in a dynamic queueing setting.
- The optimal signaling mechanism under a fixed price has a
threshold structure.
- Under optimal fixed price, optimal signaling achieves the
- ptimal revenue under state-dependent prices.
Information Design exploits the information asymmetry between a platform and its users to improve design objectives.
- An important tool in a platform’s arsenal.
SLIDE 104
Thank you!
(paper available at: https://ssrn.com/abstract=2964093)
SLIDE 105
SLIDE 106
References
SLIDE 107 Exact Thresholds
Suppose u(n) = 1 − c(n + 1) with c ∈ (0, 1). Then, for each p ∈ [0, 1 − c], the threshold mechanism σx is optimal for x = N ∗ + q∗, where N ∗ =
c
− 1
∞ if λ ≤ 1 −
c 1−p;
log(λ) (Wi (−κe−κ) + κ)
with κ =
c
−
1 1−λ
- log(λ) and where i = 0 when λ > 1 and i = −1
when 1 −
c 1−p < λ < 1. For all values of λ < ∞, we have
q∗ =
- k<N ∗ λk(1 − p − c(k + 1))
λN ∗(c(N ∗ + 1) + p − 1) .