Calendrier du 10 octobre 2022
Roy Seminar (ADRES)
Du 10/10/2022 de 17:00 à 18:15
Salle R1-09, Campus Jourdan, 75014 Paris
HE Junnan (Sciences Po)
*Learning from Viral Content - (with Krishna Dasaratha)
We study learning on social media using an equilibrium model where users interact with shared news stories. Rational users arrive sequentially and each observes an original story (i.e., a private signal) and a sample of predecessors' stories in a news feed, then decides which stories to share. Sampled news stories depend on what predecessors share as well as the sampling algorithm, which represents a design choice of the platform. We focus on how much the algorithm relies on virality (how many times a story has been previously shared) when generating news feeds. Showing users more viral stories can increase information aggregation, but can also generate steady states where most shared stories are wrong. Such misleading steady states self-perpetuate, as users who observe these wrong stories develop wrong beliefs, and thus rationally continue to share them. Moreover, these bad steady states appear discontinuously.
Econometrics Seminar
Du 10/10/2022 de 16:00 à 17:15
PSE, room R1-13
SUN Liyang (CEMFI)
Empirical Welfare Maximization with Constraints
When designing eligibility criteria for welfare programs, policymakers naturally want to target the individuals who will benefit the most. This paper proposes two new econometric approaches to selecting an optimal eligibility criterion when individuals’ costs to the program are unknown and need to be estimated. One is designed to achieve the highest benefit possible while satisfying a budget constraint with high probability. The other is designed to optimally trade off the benefit and the cost from violating the budget constraint. The setting I consider extends the previous literature on Empirical Welfare Maximization by allowing for uncertainty in estimating the budget needed to implement the criterion, in addition to its benefit. Consequently, my approaches improve the existing approach as they can be applied to settings with imperfect take-up or varying program needs. I illustrate my approaches empirically by deriving an optimal budget-constrained Medicaid expansion in the US.
Texte intégral
Régulation et Environnement
Du 10/10/2022 de 12:00 à 13:15
Salle R1-09, Campus Jourdan, 75014 Paris
NIEDERMAYER Andras (Cergy Paris Université)
*Rational Panic Purchases
We analyze rational panic purchases in a two-period model that incorporates uncertainty about sellers’ capacity and buyers’ need for the good. Even if sellers have enough capacity to satisfy demand, there may be shortages because consumers panic purchase. We show that panics can only occur if consumers are risk averse or in noncompetitive equilibria. In noncompetitive equilibria, sellers initially price below opportunity cost to induce a panic and achieve higher profits later. Conventional wisdom for various policies may be overturned when it comes to preventing panic purchases: rationing, price caps, information policy, changes of consumption tax, and restrictions on resellers.