What drives failure to maximize payoffs in the lab ? A test of the inequality aversion hypothesis

In experiments based on the Beard and Beil (1994) game, second movers very often fail to select the decision that maximizes both players payoff. This note reports on a new experimental treatment, in which we neutralize the potential effect of inequality aversion on the likelihood of this behavior. We show this behavior is robust to this change, even after allowing for repetition-based learning.Coordination failure, laboratory experiments, aversion to inequality.

Learning, words and actions : experimental evidence on coordination-improving information

This paper reports experimental results from a one-shot game with two Nash equilibria: the first one is efficient, the second one relies on weakly dominated strategies. The experimental treatments consider three information-enhancing mechanisms in the game: simple repetition, cheap-talk messages and observation of past actions from the current interaction partner. Our experimental results show the use of dominated strategies is quite widespread. Any kind of information (through learning, words or actions) increases efficiency. As regards coordination, we find that good history performs better than good messages; but bad history performs worse than bad messages.Coordination game, communication, cheap-talk, observation.

What drives failure to maximize payoffs in the lab? A test of the inequality aversion hypothesis

URL des Documents de travail : http://centredeconomiesorbonne.cnrs.fr/publications/ Voir aussi l'article basé sur ce document de travail paru dans "Review of Economic Design, 18, 243–264, (2014)Documents de travail du Centre d'Economie de la Sorbonne 2011.36 - ISSN : 1955-611XIn experiments based on the Beard and Beil (1994) game, second movers very often fail to select the decision that maximizes both players payoff. This note reports on a new experimental treatment, in which we neutralize the potential effect of inequality aversion on the likelihood of this behavior. We show this behavior is robust to this change, even after allowing for repetition-based learning.Dans les expériences en laboratoire fondées sur le jeu de Beard et Beil (1994), les joueurs chargés de décider en second échouent très souvent à prendre la décision qui maximise simultanément les gains des deux joueurs en présence. Ce court article présente les résultats d'une expérience dont le protocole neutralise les effets potentiels de l'aversion à l'inégalité. Les comportements observés sont tout à fait robustes à ce changement dans l'environnement, y compris après un certain nombre de répétitions du jeu statique

What drives failure to maximize payoffs in the lab? A test of the inequality aversion hypothesis

International audienceExperiments based on the Beard and Beil (1994) two-player coordination game robustly show that coordination failures arise as a result of two puzzling behaviors: (i) subjects are not willing to rely on others' self-interested maximization, and (ii) self-interested maximization is not ubiquitous. Such behavior is often considered to challenge the relevance of subgame perfectness as an equilibrium selection criterion, since weakly dominated strategies are actually used. We report on new experiments investigating whether inequality in payoffs between players, maintained in most lab implementations of this game, drives such behavior. Our data clearly show that the failure to maximize personal payoffs, as well as the fear that others might act this way, do not stem from inequality aversion. This result is robust to varying the saliency of decisions, repetition-based learning and cultural differences between France and Poland

Developing a national birth cohort for child health research using a hospital admissions database in England: The impact of changes to data collection practices

BACKGROUND: National birth cohorts derived from administrative health databases constitute unique resources for child health research due to whole country coverage, ongoing follow-up and linkage to other data sources. In England, a national birth cohort can be developed using Hospital Episode Statistics (HES), an administrative database covering details of all publicly funded hospital activity, including 97% of births, with longitudinal follow-up via linkage to hospital and mortality records. We present methods for developing a national birth cohort using HES and assess the impact of changes to data collection over time on coverage and completeness of linked follow-up records for children. METHODS: We developed a national cohort of singleton live births in 1998-2015, with information on key risk factors at birth (birth weight, gestational age, maternal age, ethnicity, area-level deprivation). We identified three changes to data collection, which could affect linkage of births to follow-up records: (1) the introduction of the "NHS Numbers for Babies (NN4B)", an on-line system which enabled maternity staff to request a unique healthcare patient identifier (NHS number) immediately at birth rather than at civil registration, in Q4 2002; (2) the introduction of additional data quality checks at civil registration in Q3 2009; and (3) correcting a postcode extraction error for births by the data provider in Q2 2013. We evaluated the impact of these changes on trends in two outcomes in infancy: hospital readmissions after birth (using interrupted time series analyses) and mortality rates (compared to published national statistics). RESULTS: The cohort covered 10,653,998 babies, accounting for 96% of singleton live births in England in 1998-2015. Overall, 2,077,929 infants (19.5%) had at least one hospital readmission after birth. Readmission rates declined by 0.2% percentage points per annual quarter in Q1 1998 to Q3 2002, shifted up by 6.1% percentage points (compared to the expected value based on the trend before Q4 2002) to 17.7% in Q4 2002 when NN4B was introduced, and increased by 0.1% percentage points per annual quarter thereafter. Infant mortality rates were under-reported by 16% for births in 1998-2002 and similar to published national mortality statistics for births in 2003-2015. The trends in infant readmission were not affected by changes to data collection practices in Q3 2009 and Q2 2013, but the proportion of unlinked mortality records in HES and in ONS further declined after 2009. DISCUSSION: HES can be used to develop a national birth cohort for child health research with follow-up via linkage to hospital and mortality records for children born from 2003 onwards. Re-linking births before 2003 to their follow-up records would maximise potential benefits of this rich resource, enabling studies of outcomes in adolescents with over 20 years of follow-up

Learning to deal with repeated shocks under strategic complementarity: An experiment

Experimental evidence shows that the rational expectations hypothesis fails to characterize the path to equilibrium after an exogenous shock when actions are strategic complements. Under identical shocks, however, repetition allows adaptive learning, so that inertia in adjustment should fade away with experience. If this finding proves to be robust, inertia in adjustment may be irrelevant among experienced agents. The conjecture in the literature is that inertia would still persist, perhaps indefinitely, in the presence of real-world complications such as nonidentical shocks. Herein, we empirically test the conjecture that the inertia in adjustment is more persistent if the shocks are nonidentical. For both identical and nonidentical shocks, we find persistent inertia and similar patterns of adjustment that can be explained by backward-looking expectation rules. A reformulation of naïve expectations with similarity-based learning approach is found to have a higher predictive power than rational and trend-following rules

How can we make international comparisons of infant mortality in high income countries based on aggregate data more relevant to policy?

BACKGROUND: Infant mortality rates are commonly used to compare the health of populations. Observed differences are often attributed to variation in child health care quality. However, any differences are at least partly explained by variation in the prevalence of risk factors at birth, such as low birth weight. This distinction is important for designing interventions to reduce infant mortality. We suggest a simple method for decomposing inter-country differences in crude infant mortality rates into two metrics representing risk factors operating before and after birth. METHODS: We used data from 7 European countries participating in the EURO-PERISTAT project in 2010. We calculated crude and birth weight-standardised stillbirth and infant mortality rates using Norway as the standard population. We decomposed between-country differences in crude stillbirth and infant mortality rates into the within-country difference in crude and birth weight-standardised stillbirth and infant mortality rates (metric 1), reflecting prenatal risk factors, and the between-country difference in birth weight-standardised stillbirth and infant mortality rates (metric 2), reflecting risk factors operating after birth. We also calculated birth weight-specific mortality. RESULTS: Using our metrics, we showed that for England, Wales and Scotland risk factors before and after birth contributed equally to the differences in crude stillbirth and infant mortality rates relative to Norway. In Austria, Czech Republic and Switzerland the differences were driven primarily by metric 1, reflecting high rate of low birth weight. The highest values of metric 2 observed in Poland partially reflected high rates of congenital anomalies. CONCLUSIONS: Our suggested metrics can be used to guide policy decisions on preventing infant deaths through reducing risk factors at birth or improving the care of babies after birth. Aggregate data tabulated by birth weight/gestational age should be routinely collected and published in high-income countries where birth weight is reported on birth certificates

Child mortality in England compared with Sweden: a birth cohort study

BACKGROUND: Child mortality is almost twice as high in England compared with Sweden. We aimed to establish the extent to which adverse birth characteristics and socioeconomic factors explain this difference. METHODS: We developed nationally representative cohorts of singleton livebirths between Jan 1, 2003, and Dec 31, 2012, using the Hospital Episode Statistics in England, and the Swedish Medical Birth Register in Sweden, with longitudinal follow-up from linked hospital admissions and mortality records. We analysed mortality as the outcome, based on deaths from any cause at age 2–27 days, 28–364 days, and 1–4 years. We fitted Cox proportional hazard regression models to estimate the hazard ratios (HRs) for England compared with Sweden in all three age groups. The models were adjusted for birth characteristics (gestational age, birthweight, sex, and congenital anomalies), and for socioeconomic factors (maternal age and socioeconomic status). FINDINGS: The English cohort comprised 3 932 886 births and 11 392 deaths and the Swedish cohort comprised 1 013 360 births and 1927 deaths. The unadjusted HRs for England compared with Sweden were 1·66 (95% CI 1·53–1·81) at 2–27 days, 1·59 (1·47–1·71) at 28–364 days, and 1·27 (1·15–1·40) at 1–4 years. At 2–27 days, 77% of the excess risk of death in England was explained by birth characteristics and a further 3% by socioeconomic factors. At 28–364 days, 68% of the excess risk of death in England was explained by birth characteristics and a further 11% by socioeconomic factors. At 1–4 years, the adjusted HR did not indicate a significant difference between countries. INTERPRETATION: Excess child mortality in England compared with Sweden was largely explained by the unfavourable distribution of birth characteristics in England. Socioeconomic factors contributed to these differences through associations with adverse birth characteristics and increased mortality after 1 month of age. Policies to reduce child mortality in England could have most impact by reducing adverse birth characteristics through improving the health of women before and during pregnancy and reducing socioeconomic disadvantage. FUNDING: The Farr Institute of Health Informatics Research (through the Medical Research Council, Arthritis Research UK, British Heart Foundation, Cancer Research UK, Chief Scientist Office, Economic and Social Research Council, Engineering and Physical Sciences Research Council, National Institute for Health Research, National Institute for Social Care and Health Research, and the Wellcome Trust)

Asymptomatic male with grade 3 left varicocele and two children desiring vasectomy with low testosterone

Univ Fed Sao Paulo, Sao Paulo Hosp, Dept Surg, Div Urol,Human Reprod Sect, Rua Napoleao Barros,715-2 Andar, BR-04024002 Sao Paulo, BrazilUniv Fed Sao Paulo, Sao Paulo Hosp, Dept Surg, Div Urol,Human Reprod Sect, Rua Napoleao Barros,715-2 Andar, BR-04024002 Sao Paulo, BrazilWeb of Scienc

Using administrative linked datasets to explain differences in child mortality between England and Sweden

BACKGROUND: Child mortality (under-5 years old) is almost twice as high in England as in Sweden. Policy makers need to know whether preventive strategies should address adverse birth characteristics (e.g., preterm birth, low birth weight), or focus on care after birth. This PhD used administrative linked datasets in England and Sweden to determine the contribution of birth characteristics and socio-economic factors to inter-country differences in child mortality. METHODS: I developed nationally-representative birth cohorts using an administrative hospital database in England, and a medical birth register in Sweden for births in 2003-2012, with longitudinal follow-up from linked hospitalisation and mortality records. I compared all-cause mortality, and mortality from potentially preventable causes in England relative to Sweden using Cox proportional hazards regression models. The models were adjusted for birth characteristics (gestational age, birth weight, sex, congenital anomalies), and socio-economic factors (maternal age and socio-economic status). RESULTS: Birth characteristics accounted for 77% and 68% of excess risk of death in England at 2-27 days and 28-364 days, respectively. Socio-economic factors contributed a further 3% and 11%, respectively. After adjustment for all risk factors, small but statistically significant differences in mortality remained in infancy; the differences were negligible, however, at 1-4 years. The risk of respiratory tract infection-related mortality at 31-364 days in England relative to Sweden decreased from 50% to 16% after adjusting for birth characteristics, and from 58% to 32% at 1-4 years. A third of the excess mortality from sudden unexpected infant deaths in England was explained by each birth characteristics and socio-economic factors. CONCLUSIONS: The biggest reductions in child mortality in England relative to Sweden could be achieved by reducing the prevalence of adverse birth characteristics. Policies to reduce child mortality in England should focus on improving the health of women and reducing socio-economic disadvantage before and during pregnancy