Sciences Pohttp://spire.sciencespo.fr:80/dissemination/atom-publications-by-author.xml?hdl=2441/4172dtk5fp9pp9idakit7oab6vlist of publications for an author2019-09-18T11:46:38Zhttp://spire.sciencespo.fr/hdl:/2441/cpem82ltk8fgprl50i20pgomfWe provide the first analysis of the risk-sharing implications of altruism networks. Agents are embedded in a fixed network and care about each other. We study whether altruistic transfers help smooth consumption and how this depends on the shape of the network. We identify two benchmarks where altruism networks generate efficient insurance: for any shock when the network of perfect altruism is strongly connected and for any small shock when the network of transfers is weakly connected. We show that the extent of informal insurance depends on the average path length of the altruism network and that small shocks are partially insured by endogenous risk-sharing communities. We uncover complex structural effects. Under iid incomes, central agents tend to be better insured, the consumption correlation between two agents is positive and tends to decrease with network distance, and a new link can decrease or increase the consumption variance of indirect neighbors. Overall, we show that altruism in networks has a first-order impact on risk and generates specific patterns of consumption smoothing.Altruism and Risk Sharing in Networks2019-08-30T21:00:40Zhttp://spire.sciencespo.fr/hdl:/2441/ol35m4tn09k8rv98i8a7adgpbWe study a class of sender–receiver disclosure games in the lab. Our experiment relies on a graphical representation of sender's incentives in these games, and permits partial disclosure. We use local and global properties of the incentive graph to explain behavior and performance of players across different games. Sender types whose interests are aligned with those of the receiver fully disclose, while other types use vague messages. Receivers take the evidence disclosed by senders into account, and perform better in games with an acyclic graph. Senders perform better in games with a cyclic graph. The data is largely consistent with a non-equilibrium model of strategic thinking based on the iterated elimination of obviously dominated strategies.Communication with evidence in the lab2019-08-30T21:00:40Zhttp://spire.sciencespo.fr/hdl:/2441/31aa5v8jtp9p48jlhrq44psjoaWe characterize a receiver-optimal test when manipulations are possible in the form of type falsification. Optimal design exploits the following manipulator trade-off: while falsification may lead to better grades, it devalues their meaning. We show that optimal tests can be derived among falsification-proof ones. Our optimal test has a single ‘failing’ grade, and a continuum of ‘passing’ grades. It makes the manipulator indifferent across all moderate levels of falsification. Good types never fail, but bad types may pass. An optimal test delivers at least half of the full-information value to the receiver. A three-grade optimal test also performs well.Test Design Under Falsification2019-08-30T21:00:40Zhttp://spire.sciencespo.fr/hdl:/2441/5nek1jrask8ija3jouajnob09eThis note gives a new proof of Blackwell’s celebrated result. The result is a bit stronger than the classical version since the action set and the prior are fixed, and only the utility of the decision maker varies. I show directly that a decision maker has access to a larger set of joint distributions over actions and states of the world if and only if her information improves in the garbling order.A Proof of Blackwell's Theorem2019-08-30T21:00:40Zhttp://spire.sciencespo.fr/hdl:/2441/17ekir5v8r8l6qbj0nnrfv4k2hThis paper makes a first attempt at building a theory of interim Bayesian persuasion. I work in a minimalist model where a low or high type sender seeks validation from a receiver who is willing to validate high types exclusively. After learning her type, the sender chooses a complete conditional information structure for the receiver from a possibly restricted feasible set. I suggest a solution to this game that takes into account the signaling potential of the sender's choice. Interim Bayesian Persuasion: First Steps2019-08-30T21:00:40Zhttp://spire.sciencespo.fr/hdl:/2441/4kpa2fek478tla1o86g6n9jb6vThis article asks when communication with certifiable information leads to complete information revelation. We consider Bayesian games augmented by a pre-play communication phase in which announcements are made publicly. We first characterize the augmented games in which there exists a fully revealing sequential equilibrium with extremal beliefs (i.e., any deviation is attributed to a single type of the deviator). Next, we define a class of games for which existence of a fully revealing equilibrium is equivalent to a richness property of the evidence structure. This characterization enables us to provide different sets of sufficient conditions for full information disclosure that encompass and extend all known results in the literature, and are easily applicable. We use these conditions to obtain new insights in games with strategic complementarities, voting with deliberation, and persuasion games with multidimensional types.Certifiable Pre-Play Communication: Full Disclosure2019-08-30T21:00:40Zhttp://spire.sciencespo.fr/hdl:/2441/3mdje1f65o8qrqpapnmrhon2vmWe study selection rules: voting procedures used by committees to choose whether to place an issue on their agenda. At the selection stage of the model, committee members are uncertain about their final preferences. They only have some private information about these preferences. We show that voters become more conservative when the selection rule itself becomes more conservative. The decision rule has the opposite effect. We compare these voting procedures to the designation of an agenda setter among the committee and to a utilitarian social planner with all the ex interim private information.Choosing Choices: Agenda Selection With Uncertain Issues2019-08-30T21:00:40Zhttp://spire.sciencespo.fr/hdl:/2441/5umu4i0hei8jkbdr8rppdqcallThis paper studies strategic disclosure by multiple senders competing for prizes awarded by a single receiver. They decide whether to disclose a piece of information that is both verifiable and equivocal (it can influence the receiver both ways). The standard unraveling argument breaks down: if the commonly known probability that her information is favorable is high, a single sender never discloses. Competition restores full disclosure only if some of the senders are sufficiently unlikely to have favorable information. When the senders are uncertain about each other’s strength, however, all symmetric equilibria approach full disclosure as the number of candidates increases.Competing with Equivocal Information2019-08-30T21:00:40Zhttp://spire.sciencespo.fr/hdl:/2441/5mao0mthj59eebth5kqjqgtghbThis paper addresses a common criticism of certification processes: that they simultaneously generate excessive complexity, insufficient scrutiny and high rates of undue validation. We build a model of persuasion in which low and high types pool on their choice of complexity. A natural criterion based on forward induction selects the high-type optimal pooling equilibrium.When the receiver prefers rejection ex ante, the sender simplifies her report. When the receiver prefers validation ex ante, however, more complexity makes the receiver less selective, and we provide sufficient conditions that lead to complexity inflation in equilibrium.Complicating to Persuade?2019-08-30T21:00:40Zhttp://spire.sciencespo.fr/hdl:/2441/3e7u7h227p99joe00jn66f0o6dThis note offers characterizations of tightness and weak tightness. It shows that when the preference domain
is that of continuous utility functions on the outcome space, the two notions are equivalent to the outcome
closure property of Milgrom (2010a).A Note on the Tight Simplification of Mechanisms2019-08-30T21:00:40Z