Economics

In a persuasion environment where both players are ambiguity averse, Beauchêne, Li and Li (2019) show that the sender can make strictly more profits from sending ambiguous signals if the receiver cares only about his interim payoff. As in the presence of ambiguity, the receiver may not be dynamically consistent. This paper studies ambiguous persuasion when the receiver's goal is to maximize his ex-ante payoff. First of all, if the receiver is dynamically consistent, I show the sender cannot make any profits more than Bayesian persuasion. In other words, ambiguity plays a role in persuasion only through inducing dynamically inconsistent behaviors. On the other hand, if the receiver is dynamically inconsistent and is able to adjust the information structure by ignoring the undesirable messages. Two seemingly undesirable features of ambiguous persuasion, synonyms and dilation, are not always undesirable to the receiver. In fact, they are always undesirable if and only if the payoff-relevant states are binary. Nonetheless, I show that the optimal value of ambiguous persuasion in the interim setting \citep*{Beauchêne, Li and Li, 2019} cannot be achieved in the current setting.

In an election in which each voter ranks all of the candidates, we consider the head-to-head results between each pair of candidates and form a labeled directed graph, called the margin graph, which contains the margin of victory of each candidate over each of the other candidates. A central issue in developing voting methods is that there can be cycles in this graph, where candidate A defeats candidate B , B defeats C , and C defeats A . In this paper we apply the central limit theorem, graph homology, and linear algebra to analyze how likely such situations are to occur for large numbers of voters. There is a large literature on analyzing the probability of having a majority winner; our analysis is more fine-grained. The result of our analysis is that in elections with the number of voters going to infinity, margin graphs that are more cyclic in a certain precise sense are less likely to occur.

We use Hölder's inequality to get simple derivations of certain economic formulas involving CES, Armington, or n -stage Armington functions.

We present a necessary and sufficient condition for Alt's system to be represented by a concave utility function. This condition can be seen as an extension of Gossen's first law, and thus has an economic interpretation. Together with the above result, we present a rigorous proof of Alt's representation theorem on a Hausdorff, separable, and path-connected topological space, and provide a necessary and sufficient condition for Alt's utility to be continuously differentiable.

I provide an axiomatization of stochastic utility over two periods, stating testable necessary and sufficient conditions under which an agent's choice behavior under exogenous menu selection can be modeled by a pair of random utility functions. Although static random utility is characterized by a single axiom, Block-Marschak nonnegativity, I demonstrate that an additional notion of marginal consistency is needed for the two-period axiomatization. In particular, when each period's choice set has size three, I restate the characterization using the simpler axiom of stochastic regularity. I conclude by stating several corollaries, including an axiomatization of stochastic utility with full support and an axiomatization of n-period stochastic utility.

This paper develops a new model of business cycles. The model is economical in that it is solved with an aggregate demand-aggregate supply diagram, and the effects of shocks and policies are obtained by comparative statics. The model builds on two unconventional assumptions. First, producers and consumers meet through a matching function. Thus, the model features unemployment, which fluctuates in response to aggregate demand and supply shocks. Second, wealth enters the utility function, so the model allows for permanent zero-lower-bound episodes. In the model, the optimal monetary policy is to set the interest rate at the level that eliminates the unemployment gap. This optimal interest rate is computed from the prevailing unemployment gap and monetary multiplier (the effect of the nominal interest rate on the unemployment rate). If the unemployment gap is exceedingly large, monetary policy cannot eliminate it before reaching the zero lower bound, but a wealth tax can.

We conduct a sequential social-learning experiment where subjects each guess a hidden state based on private signals and the guesses of a subset of their predecessors. A network determines the observable predecessors, and we compare subjects' accuracy on sparse and dense networks. Accuracy gains from social learning are twice as large on sparse networks compared to dense networks. Models of naive inference where agents ignore correlation between observations predict this comparative static in network density, while the finding is difficult to reconcile with rational-learning models.

In this study, we consider traveler coupon redemption behavior from the perspective of an urban mobility service. Assuming traveler behavior is in accordance with the principle of utility maximization, we first formulate a baseline dynamical model for traveler's expected future trip sequence under the framework of Markov decision processes and from which we derive approximations of the optimal coupon redemption policy. However, we find that this baseline model cannot explain perfectly observed coupon redemption behavior of traveler for a car-sharing service. To resolve this deviation from utility-maximizing behavior, we suggest a hypothesis that travelers may not be aware of all coupons available to them. Based on this hypothesis, we formulate an inattention model on unawareness, which is complementary to the existing models of inattention, and incorporate it into the baseline model. Estimation results show that the proposed model better explains the coupon redemption dataset than the baseline model. We also conduct a simulation experiment to quantify the negative impact of unawareness on coupons' promotional effects. These results can be used by mobility service operators to design effective coupon distribution schemes in practice.

An indivisible object may be sold to one of n agents who know their valuations of the object. The seller would like to use a revenue-maximizing mechanism but her knowledge of the valuations' distribution is scarce: she knows only the means (which may be different) and an upper bound for valuations. Valuations may be correlated. Using a constructive approach based on duality, we prove that a mechanism that maximizes the worst-case expected revenue among all deterministic dominant-strategy incentive compatible, ex post individually rational mechanisms is such that the object should be awarded to the agent with the highest linear score provided it is nonnegative. Linear scores are bidder-specific linear functions of bids. The set of optimal mechanisms includes other mechanisms but all those have to be close to the optimal linear score auction in a certain sense. When means are high, all optimal mechanisms share the linearity property. Second-price auction without a reserve is an optimal mechanism when the number of symmetric bidders is sufficiently high.

We consider the interim core of normal form cooperative games and exchange economies with incomplete information based on the partition model. We develop a solution concept that we can situate roughly between Wilson's coarse core and Yannelis's private core. We investigate the interim negotiation of contracts and address the two situations of contract delivery: interim and ex post. Our solution differs from Wilson's concept because the measurability of strategies in our solution is postponed until the consumption date (assumed with respect to the information that will be known by the players at the consumption date). For interim consumption, our concept differs from Yannelis's private core because players can negotiate conditional on proper common knowledge events in our solution, which strengthens the interim aspect of the game, as we will illustrate with examples.