scholarly journals An Experimental Study of Self-Enforcing Coalitions

Games ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 31 ◽  
Author(s):  
Karl Jandoc ◽  
Ruben Juarez

We study a model in which agents endowed with power compete for a divisible resource by forming coalitions with other agents. The coalition with the greatest power wins the resource and divides it among its members via proportional sharing. We conduct an economic experiment using this model to investigate possible behavioral factors that may explain deviations from theoretical predictions. The main findings show that agents display rational behavior when forming coalitions, especially when they know that a large proportion of their opponents play myopic strategies from the outset. Over time, however, agents learn to behave more strategically and even more rationally, thus enabling agents to display more of the behavior predicted by the coalition formation model with farsighted agents.

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ladjane Santos Wolmer de Melo ◽  
Maria Verônica Monteiro de Abreu ◽  
Bernuarda Roberta de Oliveira Santos ◽  
Maria das Graças Washington Casimiro Carr ◽  
Maria Fernanda Aparecida Moura de Souza ◽  
...  

Abstract Background Healthcare-associated infections (HAIs) are relevant in developing countries where frequencies can be at least 3 times higher than in developed countries. The purpose of this research was to describe the intervention implemented in intensive care units (ICUs) to reduce HAIs through collaborative project and analyze the variation over 18 months in the incidence density (ID) of the three main HAIs: ventilator associated pneumonia (VAP), central line-associated bloodstream infections (CLABSIs) and catheter-related urinary tract infections (CAUTIs) and also the length of stay and mortality in these ICUs. Methods A quasi-experimental study in five public adult clinical-surgical ICUs, to reduce HAIs, through interventions using the BTS-IHI “Improvement Model”, during 18 months. In the project, promoted by the Ministry of Health, Brazilian philanthropic hospitals certified for excellence (HE), those mostly private, certified as excellence and exempt from security contributions, regularly trained and monitored public hospitals in diagnostics, data collection and in developing cycles to improve quality and to prevent HAIs (bundles). In the analysis regarding the length of stay, mortality, the IDs of VAP, CLABSIs and CAUTIs over time, a Generalized Estimating Equation (GEE) model was applied for continuous variables, using the constant correlation (exchangeable) between assessments over time. The model estimated the average difference (β coefficient of the model) of the measures analyzed during two periods: a period in the year 2017 (prior to implementing the project) and in the years 2018 and 2019 (during the project). Result A mean monthly reduction of 0.427 in VAP ID (p = 0.002) with 33.8% decrease at the end of the period and 0.351 in CAUTI ID (p = 0.009) with 45% final decrease. The mean monthly reduction of 0.252 for CLABSIs was not significant (p = 0.068). Length of stay and mortality rates had no significant variation. Conclusions Given the success in reducing VAP and CAUTIs in a few months of interventions, the achievement of the collaborative project is evident. This partnership among public hospitals/HE may be applied to other ICUs including countries with fewer resources.


2019 ◽  
Vol 55 (11) ◽  
Author(s):  
C. S. Akondi ◽  
K. Bantawa ◽  
D. M. Manley ◽  
S. Abt ◽  
P. Achenbach ◽  
...  

Abstract.This work measured $ \mathrm{d}\sigma/\mathrm{d}\Omega$dσ/dΩ for neutral kaon photoproduction reactions from threshold up to a c.m. energy of 1855MeV, focussing specifically on the $ \gamma p\rightarrow K^0\Sigma^+$γp→K0Σ+, $ \gamma n\rightarrow K^0\Lambda$γn→K0Λ, and $ \gamma n\rightarrow K^0 \Sigma^0$γn→K0Σ0 reactions. Our results for $ \gamma n\rightarrow K^0 \Sigma^0$γn→K0Σ0 are the first-ever measurements for that reaction. These data will provide insight into the properties of $ N^{\ast}$N* resonances and, in particular, will lead to an improved knowledge about those states that couple only weakly to the $ \pi N$πN channel. Integrated cross sections were extracted by fitting the differential cross sections for each reaction as a series of Legendre polynomials and our results are compared with prior experimental results and theoretical predictions.


2015 ◽  
Vol 5 (2) ◽  
pp. 261-275
Author(s):  
Andrew W. Bausch

This paper uses a laboratory experiment to examine how different rules for re-selecting the leader of a group affects how that leader builds a winning coalition. Leaders play an inter-group game and then distribute winnings from that game within their group before standing for re-selection. The results of the experiment show that leaders of groups with large winning coalition systems rely heavily on distributing winnings through public goods, while leaders of groups with small winning coalition systems are more likely to target specific citizens with private goods. Furthermore, the experiment shows that supporters of small coalition leaders benefit from that support in future rounds by receiving more private goods than citizens that did not support the leader. Meanwhile, citizens that support a large coalition leader do not benefit from this support in future rounds. Therefore, small coalition leaders target individual citizens to maintain a coalition over time in a way not possible in a group with a large winning coalition. Finally, in the experiment, small coalition leaders increased their payoffs over time, suggesting that once power has been consolidated, small coalition leaders narrow their coalition.


2021 ◽  
Vol 152 (A4) ◽  
Author(s):  
G Thomas ◽  
T Turner ◽  
T Andrewartha ◽  
B Morris

During replenishment at sea operations the interaction between the two vessels travelling side by side can cause significant motions in the smaller vessel and affect the relative separation between their replenishment points. A study into these motions has been conducted including theoretical predictions and model experiments. The model tests investigated the influence of supply ship displacement and longitudinal separation on the ships’ motions. The data obtained from the experimental study has been used to validate a theoretical ship motion prediction method based on a 3-D zero-speed Green function with a forward speed correction in the frequency domain. The results were also used to estimate the expected extreme roll angle of the receiving vessel, and the relative motion between the vessels, during replenishment at sea operations in a typical irregular seaway. A significant increase in the frigate’s roll response was found to occur with an increase of the supply ship displacement, whilst a reduction in motion for the receiving vessel resulted from an increase in longitudinal separation between the vessels. It is proposed that to determine the optimal vessel separation it is vital that the motions of the vessels are not considered in isolation and all motions need to be considered for both vessels simultaneously.


1968 ◽  
Vol 10 (2) ◽  
pp. 121-132 ◽  
Author(s):  
C. M. Edwards ◽  
J. Halling

The paper describes an experimental study of the plastic interaction of triangular shaped lead model asperities deformed under conditions of plane strain. The investigation yields values of the normal and tangential force variations throughout the junction interaction and details of the plastic deformation particularly in relation to junction growth. A number of asperity interfacial conditions are considered ranging from complete adhesion to very low shear strengths achieved using p.t.f.e. strip. The experimental results are compared with an earlier theoretical solution to this problem and show reasonable agreement with the theoretical predictions. In particular it is shown that the normal force, which is usually compressive, may become tensile for conditions of high adhesion between the asperities. This leads to very high values of the macroscopic friction coefficient such as occur in hard vacuum situations. The experimental results for the various surface conditions show sufficient agreement with theoretical predictions to justify the use of this type of theoretical approach for the wider study of the friction and wear of mating surfaces.


Behaviour ◽  
1997 ◽  
Vol 134 (11-12) ◽  
pp. 881-890 ◽  
Author(s):  
Camilla Kunz ◽  
Anders Brodin

AbstractWe allowed seven willow tits, Parus montanus, to store and retrieve with retention intervals of 1, 7, 21 and 56 days, in four experimental rooms. Retrieval success decreased over time, indicating a decaying memory for cache locations. Compared to what could be expected by chance, retrieval success was better after all retention intervals. Our results suggest that - after the longer retention intervals - this might depend on preferences for certain types of caching locations rather than memory. If both general and individual preferences are controlled for, birds retrieved significantly better than expected one and seven days after storing, but not later than that.


SPE Journal ◽  
2018 ◽  
Vol 23 (05) ◽  
pp. 1768-1783 ◽  
Author(s):  
Mahmood Reza Yassin ◽  
Ali Habibi ◽  
Ashkan Zolfaghari ◽  
Sara Eghbali ◽  
Hassan Dehghanpour

Summary In this study, we use a custom-designed visual cell to investigate nonequilibrium carbon dioxide (CO2)/oil interactions under high-pressure/high-temperature conditions. We visualize the CO2/oil interface and measure the visual-cell pressure over time. We perform five sets of visualization tests. The first three tests aim at investigating interactions of gaseous (g), liquid (l), and supercritical (sc) CO2 with a Montney (MTN) oil sample. In the fourth test, to visualize the interactions in the bulk oil phase, we replace the opaque MTN oil with a translucent Duvernay (DUV) light oil (LO). Finally, we conduct an N2(sc)/oil test to compare the results with those of CO2(sc)/oil test. We also compare the results of nonequilibrium CO2/oil interactions with those obtained from conventional pressure/volume/temperature (PVT) tests. Results of the first three tests show that oil immediately expands upon injection of CO2 into the visual cell. CO2(sc) leads to the maximum oil expansion followed by CO2(l) and CO2(g). Furthermore, the rate of oil expansion in the CO2(sc)/oil test is higher than that in CO2(l)/oil and CO2(g)/oil tests. We also observe extracting and condensing flows at the CO2(l)/oil and CO2(sc)/oil interfaces. Moreover, we observe density-driven fingers inside the LO phase because of the local increase in the density of LO. The results of PVT tests show that the density of the CO2/oil mixture is higher than that of the CO2-free oil, explaining the density-driven natural convection during CO2(sc) injection into the visual cell. We do not observe either extracting/condensing flows or density-driven mixing for the N2(sc)/oil test, explaining the low expansion of oil in this test. The results suggest that the combination of density-driven natural convection and extracting/condensing flows enhances CO2(sc) dissolution into the oil phase, leading to fast oil expansion after CO2(sc) injection into the visual cell.


Author(s):  
Rishika Rishika ◽  
Sven Feurer ◽  
Kelly L Haws

Abstract Licensing is a well-documented form of justifying individual indulgent choices, but less is known about how licensing affects food decision-making patterns over time. Accordingly, we examine whether consumers incorporate licensing strategically and deliberately in their long-term consumption patterns and identify reward programs as a context in which strategic licensing is likely to occur. We propose that members with lower-calorie consumption patterns strategically indulge more on reward purchase occasions, and that forethought is required for such an effect to occur. A longitudinal study analyzing 272,677 real food purchases made by 7,828 consumers over a 14-month period provides striking evidence of our key proposition. An exploration of the inter-purchase time-related aspect of purchase acceleration suggests that forethought on behalf of consumers is necessary for strategic licensing to occur. A subsequent experimental study (N = 605) comprising five consecutive choice occasions provides additional evidence of forethought by demonstrating that strategic licensing occurs only when expected (but not windfall reward) occasions are involved, and by showing that anticipated negative affect for not indulging is the driving mechanism. We conclude with a discussion of the implications of our results for consumers, managers, and public policy makers.


Author(s):  
Soňa Szomolányi ◽  
Alexander Karvai

In Slovakia, the main lines of conflict that determine coalition formation have changed over time. Iinitially the conflicts were based on national-ethnic issues, later this was followed by disagreement over the direction of reforms and the European integration process. Eventually they have settled around socioeconomic policies with alternating right and left governments in power. Only three coalition cabinets have served the full parliamentary terms, and all of them have both enjoyed a majority support in Parliament and included a dominant large party. In contrast, coalitions without a major leading party, and where the power structure has been more evenly distributed, have been more likely to terminate due to inter-party conflicts before the end of the full constitutionally mandated term. The coalitions of the second type coalitions have also been pursuing more of consensual style of politics. They have been based on social-economic policy agreement between the parties but differed considerably in terms of the GAL-TAN dimension. While socioeconomic policies appear is a strong driving force in coalition bargaining, the second (GAL-TAN) dimension tends to matters more when it comes to the survival of the coalition. In terms of coalition governance, six out twelve cabinets represented the Prime Minister Dominated model. The cabinets with a leading party (HZDS, SDKÚ-DS, and SMER-DS) did not have as many internal conflicts as the cabinets with a relatively even power distribution. The latter type of cabinets relied instead on their ability to negotiate and compromise in the name of consensus and so they represent a Coalition Compromise Model.


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