Using public goods games in a laboratory setting, we study team-level production, where two teams compete for the resources of a common-member who can benefit from and provide effort in both teams. Intrinsically, the common-member faces divided loyalties. We examine such competition in a setting in which the common-member has productive abilities equal to that of the other team members (dedicated-members), and in two settings where he/she has greater relative potential. When effort (contributions) by the common-member have greater productivity (coupled with higher opportunity costs to contribute) in providing the public good relative to that of dedicated-members, we find team performance is not significantly increased. On the other hand, when the common-member has a greater endowment, sufficient to match the absolute contributions of team members in both teams, there is a significant increase in team performance. The evidence suggests that a norm of reciprocity by dedicated-members based on absolute contributions of the common-member better explains behavior than a norm based on the value added of the common-member's contributions. This behavior, along with fairness norms elicited in a survey, suggests that on average dedicated members do not sufficiently incorporate the common-members' higher opportunity costs in the treatment where his/her productivity is increased. This setting provides an important illustration of where the behavioral response to the type of inequality matters, leading to differences in team efficiency.

Abundant evidence suggests that high levels of contributions to public goods can be sustained through self-governed monitoring and sanctioning. This experimental study investigates the effectiveness of decentralized sanctioning institutions in alternative punishment networks. Our results show that the structure of punishment network significantly affects allocations to the public good. In addition, we observe that network configurations are more important than punishment capacities for the levels of public good provision, imposed sanctions and economic efficiency. Lastly, we show that targeted revenge is a major driver of anti-social punishment.

A burgeoning literature in experimental studies of the Voluntary Contribution Mechanism focuses on the ability of institutions that allow the monitoring, sanctioning, and/or rewarding of others to facilitate cooperation. In this paper rewards and sanctions are examined in a one-shot VCM setting that so far has been unexplored in the literature. The study finds that while some subjects are willing to reward and sanction others at a personal cost, the opportunity to reward or sanction is ineffective in facilitating cooperation relative to previous experiments in which a repeated game environment is employed. The study also compares behavior in an environment in which the imposition of rewards and sanctions is certain to an environment in which imposition is uncertain. The expected value of the reward or sanction is kept constant across environments to focus simply on the effect of uncertainty about imposition. Uncertainty does not change behavior in a significant way, either in the level of cooperation or the willingness of individuals to impose rewards or sanctions.

We present experimental evidence for decision settings where public good providers compete for endogenous rewards which are donations (transfers) offered by outside donors. Donors receive benefits from public good provision but cannot provide the good themselves. The performance of three competition mechanisms is examined in relation to the level of public good provision and transfers offered by donors. In addition to a contest where transfers received by public good providers are proportional to effort, we study two contests with exclusion from transfers, namely a winner-takes-all and a loser-gets-nothing. We compare behavior in these three decision settings to the default setting of no-contest (no-transfers). Results for this novel decision environment with endogenous transfers show that donors offer transfers (contest prizes) at similar levels across contests and contributions to the public good are not significantly different in the three contests settings, but are consistently and significantly higher in all contests compared to the setting with no-transfers. Initially, the winner-takes-all setting leads to a significantly higher increase in public good contributions compared to the other two contests; but this difference diminishes across decision rounds.

Experiments are reported that add to the growing literature on the voluntary provision of public goods. Information conditions are manipulated to address whether early findings of above-equilibrium contributions to a public good are a result of complete information regarding the symmetry of the game. No significant information effect was found. Further, by examining designs with an interior Nash equilibrium, this research suggests that the nonzero contributions observed in the previous dominant strategy environments, where the prediction was a zero level of provision of the public good, were not simply transitional errors as the system converged to a boundary equilibrium.

Using an appropriation game setting, we examine individual responses to changes in a groups’ vulnerability to a probabilistic loss (L) of a public good. The probabilistic loss parameter entails losing 10, 50 or 90% of the value of the public good that is maintained through cooperation, where the likelihood of the loss decreases in total group cooperation. By design, the expected marginal net benefits to an individual and the expected harm to others depends endogenously on the individuals’ expectations of group cooperation and exogenously on the magnitude of the loss parameter. We find that individual cooperation is greater when forecasts of total group cooperation are greater and where the magnitude of the probabilistic loss is larger. There is, however, an interesting asymmetry in responses by two subgroups. Subjects who are pessimistic regarding total group cooperation decrease cooperation the higher the magnitude of the probabilistic loss and their decisions are tied systematically to changes in their expectations of other’s cooperation. On the other hand, subjects who are optimistic regarding total group cooperation are found to be more cooperative, but their decisions are not systematically tied to changes in expectations of others’ cooperation.

Ventilator-associated pneumonia (VAP) is a well-established cause of morbidity in critically ill patients. Current VAP criteria exclude patients on extracorporeal membrane oxygenation (ECMO). This retrospective analysis tests the validity of VAP in this population, as well as a new proposed diagnostic criterion for ECMO-associated pneumonia.

The angular correlation is a method for measuring the distribution of structure in the Universe, through the statistical properties of the angular distribution of galaxies on the sky. We measure the angular correlation of galaxies from the second data release of the GaLactic and Extragalactic All-sky Murchison Widefield Array eXtended survey (GLEAM-X) survey, a low-frequency radio survey covering declinations below $+30^\circ$. We find an angular distribution consistent with the $\Lambda$CDM cosmological model assuming the best fitting cosmological parameters from Planck Collaboration et al. (2020, A&A, 641, A6). We fit a bias function to the discrete tracers of the underlying matter distribution, finding a bias that evolves with redshift in either a linear or exponential fashion to be a better fit to the data than a constant bias. We perform a covariance analysis to obtain an estimation of the properties of the errors, by analytic, jackknife, and sample variance means. Our results are consistent with previous studies on the topic, and also the predictions of the $\Lambda$CDM cosmological model.