2,108 research outputs found
Pinocchio's Pupil: Using Eyetracking and Pupil Dilation to Understand Truth Telling and Deception in Sender-Receiver Games
We report experiments on sender-receiver games with an incentive for senders to exaggerate. Subjects "overcommunicate" -- messages are more informative of the true state than they should be, in equilibrium. Eyetracking shows that senders look at payoffs in a way that is consistent with a level-k model. A combination of sender messages and lookup patterns predicts the true state about twice as often as predicted by equilibrium. Using these measures to infer the state would enable receiver subjects to hypothetically earn 16-21 percent more than they actually do, an economic value of 60 percent of the maximum increment
Pinocchio's Pupil: Using Eyetracking and Pupil Dilation to Understand Truth-telling and Deception in Games
Testing Game Theory in the Field: Swedish LUPI Lottery Games
Game theory is usually difficult to test precisely in the field because predictions typically
depend sensitively on features that are not controlled or observed. We conduct one such
test using field data from the Swedish lowest unique positive integer (LUPI) game. In the
LUPI game, players pick positive integers and whoever chose the lowest unique number
wins a fixed prize. Theoretical equilibrium predictions are derived assuming Poisson-
distributed uncertainty about the number of players, and tested using both field and
laboratory data. The field and lab data show similar patterns. Despite various deviations
from equilibrium, there is a surprising degree of convergence toward equilibrium. Some
of the deviations from equilibrium can be rationalized by a cognitive hierarchy model
Field and Lab Convergence in Poisson LUPI Games
In the lowest unique positive integer (LUPI) game, players pick positive integers and the
player who chose the lowest unique number (not chosen by anyone else) wins a fixed
prize. We derive theoretical equilibrium predictions, assuming fully rational players with
Poisson-distributed uncertainty about the number of players. We also derive predictions
for boundedly rational players using quantal response equilibrium and a cognitive hierarchy of rationality steps with quantal responses. The theoretical predictions are tested
using both field data from a Swedish gambling company, and laboratory data from a
scaled-down version of the field game. The field and lab data show similar patterns: in
early rounds, players choose very low and very high numbers too often, and avoid focal
("round") numbers. However, there is some learning and a surprising degree of convergence toward equilibrium. The cognitive hierarchy model with quantal responses can
account for the basic discrepancies between the equilibrium prediction and the data
Evidence of general economic principles of bargaining and trade from 2,000 classroom experiments
Standardized classroom experiments provide evidence about how well scientific results reproduce when nearly identical methods are used. We use a sample of around 20,000 observations to test reproducibility of behaviour in trading and ultimatum bargaining. Double-auction results are highly reproducible and are close to equilibrium predictions about prices and quantities from economic theory. Our sample also shows robust correlations between individual surplus and trading order, and autocorrelation of successive price changes, which test different theories of price dynamics. In ultimatum bargaining, the large dataset provides sufficient power to identify that equal-split offers are accepted more often and more quickly than slightly unequal offers. Our results imply a general consistency of results across a variety of different countries and cultures in two of the most commonly used designs in experimental economics
The Wick in the Candle of Learning: Epistemic Curiosity Activates Reward Circuitry and Enhances Memory
Curiosity has been described as a desire for
learning and knowledge, but its underlying mechanisms
are not well understood. We scanned subjects with functional
magnetic resonance imaging while they read trivia
questions. The level of curiosity when reading questions
was correlated with activity in caudate regions previously
suggested to be involved in anticipated reward. This
finding led to a behavioral study, which showed that subjects
spent more scarce resources (either limited tokens or
waiting time) to find out answers when they were more
curious. The functional imaging also showed that curiosity
increased activity in memory areas when subjects guessed
incorrectly, which suggests that curiosity may enhance
memory for surprising new information. This prediction
about memory enhancement was confirmed in a behavioral
study: Higher curiosity in an initial session was correlated
with better recall of surprising answers 1 to 2 weeks later
Improved survival after acute graft-
A cute graft- versus -host disease remains a major threat to a successful outcome after allogeneic hematopoietic cell transplantation. While improvements in treatment and supportive care have occurred, it is unknown whether these advances have resulted in improved outcome specifically among those diagnosed with acute graft- versus -host disease. We examined outcome following diagnosis of grade II-IV acute graft- versus -host disease according to time period, and explored effects according to original graft- versus -host disease prophylaxis regimen and maximum overall grade of acute graft- versus -host disease. Between 1999 and 2012, 2,905 patients with acute myeloid leukemia (56%), acute lymphoblastic leukemia (30%) or myelodysplastic syndromes (14%) received a sibling (24%) or unrelated donor (76%) blood (66%) or marrow (34%) transplant and developed grade II-IV acute graft- versus -host disease (n=497 for 1999-2001, n=962 for 2002-2005, n=1,446 for 2006-2010). The median (range) follow-up was 144 (4-174), 97 (4-147) and 60 (8-99) months for 1999-2001, 2002-2005, and 2006-2010, respectively. Among the cohort with grade II-IV acute graft- versus -host disease, there was a decrease in the proportion of grade III-IV disease over time with 56%, 47%, and 37% for 1999-2001, 2002-2005, and 2006-2012, respectively ( P <0.001). Considering the total study population, univariate analysis demonstrated significant improvements in overall survival and treatment-related mortality over time, and deaths from organ failure and infection declined. On multivariate analysis, significant improvements in overall survival ( P =0.003) and treatment-related mortality ( P =0.008) were only noted among those originally treated with tacrolimus-based graft- versus -host disease prophylaxis, and these effects were most apparent among those with overall grade II acute graft- versus -host disease. In conclusion, survival has improved over time for tacrolimus-treated transplant recipients with acute graft- versus -host disease
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