Cognition and Behavior in Two-Person Guessing Games: An Experimental Study

This paper reports experiments that elicit subjects' initial responses to 16 dominancesolvable two-person guessing games. The structure is publicly announced except for varying payoff parameters, to which subjects are given free access, game by game, through an interface that records their information searches. Varying the parameters allows strong separation of the behavior implied by leading decision rules and makes monitoring search a powerful tool for studying cognition. Many subjects' decisions and searches show clearly that they understand the games and seek to maximize their payoffs, but have boundedly rational models of others' decisions, which lead to systematic deviations from equilibrium.

Stated Beliefs and Play in Normal-Form Games

Using data on one-shot games, we investigate the assumption that players respond to underlying expectations about their opponent's behavior. In our laboratory experiments, subjects play a set of 14 two-person 3x3 games, and state first order beliefs about their opponent'sbehavior. The sets of responses in the two tasks are largely inconsistent. Rather, we findevidence that the subjects perceive the games differently when they (i) choose actions, and (ii) state beliefs _ they appear to pay more attention to the opponent's incentives when they state beliefs than when they play the games. On average, they fail to best respond to their own stated beliefs in almost half of the games. The inconsistency is confirmed by estimates of a unified statistical model that jointly uses the actions and the belief statements. There, we can control for noise, and formulate a statistical test that rejects consistency. Effects of the belief elicitation procedure on subsequent actions are mostly insignificant.

Beliefs and Actions in the Trust Game: Creating Instrumental Variables to Estimate the Causal Effect

In many economic contexts, an elusive variable of interest is the agent's expectation about relevant events, e.g. about other agents' behavior. Recent experimental studies as well as surveys have asked participants to state their beliefs explicitly, but little is known about the causal relation between beliefs and other behavioral variables. This paper discusses the possibility of creating exogenous instrumental variables for belief statements, by shifting the probabilities of the relevant events. We conduct trust game experiments where the amount sent back by the second player (trustee) is exogenously varied by a random process, in a way that informs only the first player (trustor) about the realized variation. The procedure allows detecting causal links from beliefs to actions under plausible assumptions. The IV estimates indicate a significant causal effect, comparable to the connection between beliefs and actions that is suggested by OLS analyses.Social capital, trust game, instrumental variables, belief elicitation

Beliefs and Actions in the Trust Game: Creating Instrumental Variables to Estimate the Causal Effect

In many economic contexts, an elusive variable of interest is the agent's expectation about relevant events, e.g. about other agents' behavior. Recent experimental studies as well as surveys have asked participants to state their beliefs explicitly, but little is known about the causal relation between beliefs and other behavioral variables. This paper discusses the possibility of creating exogenous instrumental variables for belief statements, by shifting the probabilities of the relevant events. We conduct trust game experiments where the amount sent back by the second player (trustee) is exogenously varied by a random process, in a way that informs only the first player (trustor) about the realized variation. The procedure allows detecting causal links from beliefs to actions under plausible assumptions. The IV estimates indicate a significant causal effect, comparable to the connection between beliefs and actions that is suggested by OLS analyses.social capital, trust game, instrumental variables, belief elicitation

Transição martensítica em filmes finos de Ni2+x+yMn1-xGa1-y

Mestrado em Engenharia FísicaEste trabalho teve dois objetivos fundamentais comuns e complementares. Desenvolvimento de uma rotina em Labview para automatização de um sistema de medidas de propriedades de transporte em função da temperaturas e/ou do campo magnético. A segunda parte do trabalho consistiu no estudo de filmes finos de Ni2MnGa com especial relevância dada à transformação martensítica. As amostras foram depositadas através da deposição em simultânea de ligas 5050 e de 5050usando RF-sputtering em substratos monocristalinos de MgO (100), Si (100) e STO (100). As amostras foram caracterizadas do ponto de vista estrutural usando difração de raio-x, SEM e EDS. A caracterização magnética foi feita através do SQUID e VSM. A caracterização elétrica foi feita usando o método das quatro pontas. As curvas R-T (resistência em função da temperatura) mostraram uma histerese térmica inicial anormal e alterações que sugerem uma dependência, para além da estrutural, de efeitos temporais. As medidas R-T com a aplicação de um campo magnético externo mostraram um deslocamento esperado da transição estrutural. A comparação qualitativa das medidas de magnetização com as previsões teóricas é satisfatória. Observa-se, no entanto, um offset que é explicado pelo carácter quase amorfo dos filmes em estudo, da composição e da temperatura.This study has two common core objectives. The first consists in developing a Labview routine to automate a system of transport properties measurement as a function of temperature and magnetic field. The second part of this work consisted in the study of Ni2MnGa thin films, with special focus on the martensitic transformation. The samples were prepared by simultaneous deposition of and target alloys by RFsputtering on single crystal substrates of MgO (100) , Si (100) and STO (100). X-ray diffraction, SEM and EDS were the tecnhiques used for structural characterization. Magnetic characterization was assessed using SQUID and VSM. The electrical characterization was done using the four point method. The R-T curves (resistance versus temperature) showed an abnormal initial thermal hysteresis and changes that suggest a dependency on, addition to structural, temporal effects. The R-T measurements, under an external applied magnetic field showed an expected structural temperature transition displacement. A qualitative comparison of the magnetization with the theoretical predictions is satisfactory. However, an offset is observed witch is explained by the almost amorphous nature of the films being studied, the composition, and temperature

Sure-thing vs. probabilistic charitable giving : experimental evidence on the role of individual differences in risky and ambiguous charitable decision-making

One of the authors, Philipp Schoenegger, has received a research funding from the Forethought Foundation and the Centre for Effective Altruism (they do not provide grant numbers).Charities differ, among other things, alongside the likelihood that their interventions succeed and produce the desired outcomes and alongside the extent that such likelihood can even be articulated numerically. In this paper, we investigate what best explains charitable giving behaviour regarding charities that have interventions that will succeed with a quantifiable and high probability (sure-thing charities) and charities that have interventions that only have a small and hard to quantify probability of bringing about the desired end (probabilistic charities). We study individual differences in risk/ambiguity attitudes, empathy, numeracy, optimism, and donor type (warm glow vs. pure altruistic donor type) as potential predictors of this choice. We conduct a money incentivised, pre-registered experiment on Prolific on a representative UK sample (n = 1,506) to investigate participant choices (i) between these two types of charities and (ii) about one randomly selected charity. Overall, we find little to no evidence that individual differences predict choices regarding decisions about sure-thing and probabilistic charities, with the exception that a purely altruistic donor type predicts donations to probabilistic charities when participants were presented with a randomly selected charity in (ii). Conducting exploratory equivalence tests, we find that the data provide robust evidence in favour of the absence of an effect (or a negligibly small effect) where we fail to reject the null. This is corroborated by exploratory Bayesian analyses. We take this paper to be contributing to the literature on charitable giving via this comprehensive null-result in pursuit of contributing to a cumulative science.Publisher PDFPeer reviewe