Target-the-two. A lab-in-the-field experiment on routinization

The paper investigates the cognitive determinants of routinization and creativity by means of a lab-in-the-field experiment run at the 20th edition of a mass gathering festival in Italy (“La Notte della Taranta”). Subjects play repeatedly the puzzle version of the Target-The-Two game (32 hands). In hands 1-16, the strategy that is optimal given the card distribution is always the same and it is the easiest to be discovered. Conversely, in hands 17-32, subjects are exposed to games where the optimal contextual strategy may differ from the one with which they have been made familiar. We investigate whether and how, in hands 17-32, subjects remain routinized on the familiar strategy, or creatively choose a different one. We define as “experts” those subjects who played the optimal contextual strategy in the overwhelming majority of hands 1-16. In hands 17-32, we find several subjects playing the familiar strategy even when it is not the optimal one, regardless of whether they are experts or not. This shows that routinization is deep-rooted in the cognitive individual process. Furthermore, routinization pays off only for inexpert subjects: creative inexpert subjects are slower and they fail to find the optimal contextual strategy in several hands. Among expert subjects instead, creative subjects, although still slower, need less moves than routinized ones to find the optimal contextual strategy

Peri-operative red blood cell transfusion in neonates and infants: NEonate and Children audiT of Anaesthesia pRactice IN Europe: A prospective European multicentre observational study

BACKGROUND: Little is known about current clinical practice concerning peri-operative red blood cell transfusion in neonates and small infants. Guidelines suggest transfusions based on haemoglobin thresholds ranging from 8.5 to 12 g dl-1, distinguishing between children from birth to day 7 (week 1), from day 8 to day 14 (week 2) or from day 15 (≥week 3) onwards. OBJECTIVE: To observe peri-operative red blood cell transfusion practice according to guidelines in relation to patient outcome. DESIGN: A multicentre observational study. SETTING: The NEonate-Children sTudy of Anaesthesia pRactice IN Europe (NECTARINE) trial recruited patients up to 60 weeks' postmenstrual age undergoing anaesthesia for surgical or diagnostic procedures from 165 centres in 31 European countries between March 2016 and January 2017. PATIENTS: The data included 5609 patients undergoing 6542 procedures. Inclusion criteria was a peri-operative red blood cell transfusion. MAIN OUTCOME MEASURES: The primary endpoint was the haemoglobin level triggering a transfusion for neonates in week 1, week 2 and week 3. Secondary endpoints were transfusion volumes, 'delta haemoglobin' (preprocedure - transfusion-triggering) and 30-day and 90-day morbidity and mortality. RESULTS: Peri-operative red blood cell transfusions were recorded during 447 procedures (6.9%). The median haemoglobin levels triggering a transfusion were 9.6 [IQR 8.7 to 10.9] g dl-1 for neonates in week 1, 9.6 [7.7 to 10.4] g dl-1 in week 2 and 8.0 [7.3 to 9.0] g dl-1 in week 3. The median transfusion volume was 17.1 [11.1 to 26.4] ml kg-1 with a median delta haemoglobin of 1.8 [0.0 to 3.6] g dl-1. Thirty-day morbidity was 47.8% with an overall mortality of 11.3%. CONCLUSIONS: Results indicate lower transfusion-triggering haemoglobin thresholds in clinical practice than suggested by current guidelines. The high morbidity and mortality of this NECTARINE sub-cohort calls for investigative action and evidence-based guidelines addressing peri-operative red blood cell transfusions strategies. TRIAL REGISTRATION: ClinicalTrials.gov, identifier: NCT02350348

Experimetrics. Econometrics for experimental economics, Peter G. Moffatt. Palgrave Macmillan, London, UK (2015). ISBN: 978-0-230-25023-9

This is a review of the book "Experimetrics: Econometrics for Experimental Economics, Peter G. Moffatt. Palgrave Macmillan, London, UK (2015). ISBN: 978-0-230-25023-9"

Zero-intelligence versus~human agents. An experimental analysis of the efficiency of double auctions and over-the-counter markets of varying sizes

We study two well‐known electronic markets: an over‐ the‐counter (OTC) market, in which each trader looks for the best counterpart through bilateral negotiations, and a double auction (DA) market, in which traders post their quotes publicly. We focus on the DA–OTC efficiency gap and show how it varies with different market sizes (10, 20, 40, and 80 traders). We compare experimental results from a sample of 6400 undergraduate students in Economics and Management with zero‐intelligence agent‐based simulations. Simulation results show that the traded quantity increases with market size under both DA and OTC. Experimental results confirm the same tendency under DA, while the share of periods in which the traded quantity is lower than the efficient one increases with market size under OTC, ultimately leading to a DA–OTC efficiency gap increasing with the market size. We rationalize these results by putting forward a simple model of OTC market as a repeated bargaining procedure under incomplete information on buyers' valuations and sellers' costs. We show that efficiency decreases slightly with size due to two counteracting effects: acceptance rates in earlier interactions decrease with size, and earlier offers increase, but not always enough to com- pensate for the decrease in acceptance rates

Incomplete-Information Models of Guilt Aversion in the Trust Game

International audienc

Incomplete-information models of guilt aversion in the trust game

In the theory of psychological games it is assumed that players’ preferences on material consequences depend on endogenous beliefs. Most of the applications of this theoretical framework assume that the psychological utility functions representing such preferences are common knowledge. However, this is often unrealistic. In particular, it cannot be true in experimental games where players are subjects drawn at random from a population. Therefore, an incomplete-information methodology is needed. We take a first step in this direction, focusing on guilt aversion in the Trust Game. In our models, agents have heterogeneous belief hierarchies. We characterize equilibria where trust occurs with positive probability. Our analysis illustrates the incomplete-information approach to psychological games and can help to organize experimental results in the Trust Game

Belief-dependent preferences and reputation: Experimental analysis of a repeated trust game

International audienceWe study in a theoretical and experimental setting the interaction between belief-dependent preferences and reputation building in a finitely repeated trust game. We focus mainly on the effect of guilt aversion. In a simple two-type model, we analyze the effect of reputation building in the presence of guilt-averse trustees and derive behavioral predictions. We test these predictions in a laboratory experiment where we elicit information on trustees’ belief-dependent preferences and disclose it to the paired trustor before the repeated game

Host Environment Shapes S. aureus Social Behavior as Revealed by Microscopy Pattern Formation and Dynamic Aggregation Analysis

Understanding how bacteria adapt their social behavior to environmental changes is of crucial importance from both biological and clinical perspectives. Staphylococcus aureus is among the most common infecting agents in orthopedics, but its recalcitrance to the immune system and to antimicrobial treatments in the physiological microenvironment are still poorly understood. By means of optical and confocal microscopy, image pattern analysis, and mathematical modeling, we show that planktonic biofilm-like aggregates and sessile biofilm lifestyles are two co-existing and interacting phases of the same environmentally adaptive developmental process and that they exhibit substantial differences when S. aureus is grown in physiological fluids instead of common lab media. Physicochemical properties of the physiological microenvironment are proposed to be the key determinants of these differences. Besides providing a new tool for biofilm phenotypic analysis, our results suggest new insights into the social behavior of S. aureus in physiological conditions and highlight the inadequacy of commonly used lab media for both biological and clinical studies of bacterial development