This paper develops a theoretical framework to think about employees' effort choices, and applies this framework to assess the ability of existing experimental designs to identify the effect of pay ...inequality on worker effort. The analysis shows that failure to control for a number of confounds—such as reciprocity towards the employer in multi-lateral gift-exchange games (vertical fairness), or the incentive to increase effort when feeling underpaid under piece rates (income targeting)—may lead to inaccurate interpretation of evidence of treatment effects. In light of these findings, the paper provides a set of recommendations on how to improve identification in the design of controlled experiments in the future.
•We develop a model to study employees' effort choices in experiments.•We formally assess the design of experiments on the effect of pay inequality on effort.•We find a number of confounds that may impair identification of treatment effects.•Confounds include vertical fairness, income targeting, repeated interactions, procedural fairness.•A set of recommendations to improve identification in experiments is provided.
Despite the renewed interest in the use of experimental designs in the fields of leadership and management over the past few decades, these designs are still relatively underutilized. Although there ...are several potential reasons for this, chief among them is misunderstanding the value of these designs. The purpose of this article is to review the role of laboratory, field, and quasi-experimental designs in management and leadership research. We first discuss the primary goals of experimental studies. Next, we examine the characteristics of experimental designs and how to distinguish laboratory, field, and quasi-experiments from one another and from non-experimental studies. Following these discussions, we provide examples of each type of experimental design and discuss their relative strengths and limitations. Finally, we discuss steps that researchers can take to increase the probability of having articles reporting experiments accepted by leadership and management journals.
In this paper, we study the correlation between cheating in the lab and cheating in the field. We conduct a laboratory experiment using a variant of the Mind game (Jiang, 2013). Payoffs above a ...certain threshold are indicative of cheating behavior. Subjects are paid their earnings by bank transfer. A fraction of the subjects is deliberately paid more than their earnings. We send subjects a reminder e-mail stating their earnings and asking them if they have received their payment. We find a significant correlation of 0.31 between cheating in the lab and in the field. Subjects with higher payoffs in the Mind game are also less likely to report the overpayment. Our results speak to the lab-field generalizability of cheating behavior.
This study investigates how people provide public goods in a network formation game. In this game, players form a network through bilateral linking, with or without a link cost; the players then ...contribute to a public good, which can benefit both themselves and their direct neighbors. Theoretically, two equilibrium goods provision strategies exist: splitting and alternation. Efficient networks are conditioned on a goods provision strategy and are less dense when the link cost increases. Our laboratory experiment indicates that subjects predominantly converge to splitting instead of alternation and can often form efficient networks. Subjects form fewer links under a higher link cost and tend to form too many links.
oTree is an open-source and online software for implementing interactive experiments in the laboratory, online, the field or combinations thereof. oTree does not require installation of software on ...subjects’ devices; it can run on any device that has a web browser, be that a desktop computer, a tablet or a smartphone. Deployment can be internet-based without a shared local network, or local-network-based even without internet access. For coding, Python is used, a popular, open-source programming language. www.oTree.org provides the source code, a library of standard game templates and demo games which can be played by anyone.
Microplastics (<5 mm) have been found in many fish species, from most marine environments. However, the mechanisms underlying microplastic ingestion by fish are still unclear, although they are ...important to determine the pathway of microplastics along marine food webs. Here we conducted experiments in the laboratory to examine microplastic ingestion (capture and swallowing) and egestion by juveniles of the planktivorous palm ruff, Seriolella violacea (Centrolophidae). As expected, fish captured preferentially black microplastics, similar to food pellets, whereas microplastics of other colours (blue, translucent, and yellow) were mostly co-captured when floating close to food pellets. Microplastics captured without food were almost always spit out, and were only swallowed when they were mixed with food in the fish's mouth. Food probably produced a ‘gustatory trap’ that impeded the fish to discriminate and reject the microplastics. Most fish (93% of total) egested all the microplastics after 7 days, on average, and 49 days at most, substantially longer than food pellets (<2 days). No acute detrimental effects of microplastics on fish were observable, but potential sublethal effects of microplastics on the fish physiological and behavioural responses still need to be tested. This study highlights that visually-oriented planktivorous fish, many species of which are of commercial value and ecological importance within marine food webs, are susceptible to ingest microplastics resembling or floating close to their planktonic prey.
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•Fish captured preferentially microplastic similar to food pellets.•Microplastics were only swallowed when mixed with food in the fish's mouth.•Food produced a ‘gustatory trap’ that impedes fish to discriminate against microplastics.•Microplastics were egested after one week on average, and a maximum of 7 weeks.•Microplastics did not have notable acute deleterious effects on the fish.
Microplastic similarity to food, and food presence together with microplastics, influence the ingestion of microplastics by visually-oriented planktivorous fish.
We quantify patient-regarding preferences by fitting a bounded rationality model to data from an incentivized laboratory experiment, where Chinese medical doctors, German medical students and Chinese ...medical students decide under different payment schemes. We find a remarkable stability in patient-regarding preferences when comparing subject pools and we cannot reject the hypothesis of equal patient-regarding preferences in the three groups. The results suggest that a health economic experiment can provide knowledge that reach beyond the student subject pool, and that the preferences of decision-makers in one cultural context can be of relevance in a very different cultural context.
•Reactor laboratory experiments are conducted in zero-powered research reactor facilities, at UTR-KINKI and KUCA.•The range of programs is extensive, covering reactor physics experiments and ...radiation detection.•A new educational program is provided at KUCA, covering exponential experiments and uranium enrichment measurements.•Introducing subcritical measurements is conducive to the fostering experts with an interest in criticality safety.
Reactor laboratory experiments are conducted in zero-powered research reactor facilities, at the University Teaching and Research Reactor (UTR in Kindai University: UTR-KINKI) and at Kyoto University Critical Assembly (KUCA), together with nuclear education through reactor physics experiments for university students. The experimental programs designed for undergraduate and graduate students at UTR-KINKI are classified into basic, intermediate, and advanced levels according to student coursework in subjects related to reactor physics and radiation detection; also developed is a curriculum of experimental programs to meet student needs. A new educational program is provided at KUCA, covering exponential experiments and uranium enrichment measurements. The range of the systematic development of programs for reactor laboratory experiments is extensive, covering reactor physics experiments and radiation detection. Notably, incorporating subcriticality measurements by the Feynman-α method in the UTR-KINKI core into the program offers outstanding opportunities for direct experience with measurement and data processing methods that involve critical approach monitoring of fuel debris. Introducing subcritical measurements is conducive to the fostering experts with an interest in criticality safety.
•A physical laboratory model was designed and used for tests with varying conditions.•The increase in the vadose zone thickness will intensify the buffer effect.•Karstification degree impacts ...infiltration differently with or without epikarst.•Epikarst influences the soil layer's drainage channel and storage capacity.
Groundwater in karst systems is a vital resource, which is often highly vulnerable to contaminants that infiltrate through the vadose zone. Understanding the processes of water and contaminant infiltration in the vadose zone is extremely important for protecting and managing karst water resources. A laboratory-scale physical model based on a typical conceptual model of the karst vadose zone was constructed to characterize the influence of the rainfall intensity and internal structure on the infiltration process and solute transport in the karst vadose zone under controlled conditions. Five factors, including the rainfall intensity, the surface slope, the degree of karstification, the thickness of the transfer zone, and the existence of epikarst, were considered in laboratory experiments. A corresponding lumped-parameter model was subsequently developed to further analyze and investigate the water and solute infiltration processes in the laboratory scale physical model. Recession- and breakthrough curves generated from the lab experiments and the water and solute loss from each reservoir generated from the simulation results were analyzed. The downward trend of breakthrough curves' peak value and the variation of solute loss's proportion in three rainfall events demonstrate that both the increase in thickness and karstification degree will intensify the buffer effect of the karst vadose zone, and this buffer effect is mainly affected by the slow flow system which can be inferred from the increasing percentage of cumulative discharge of slow reservoir (qS). With increasing karstification degree, the recession coefficient (α) exhibits opposite trends depending on the existence of epikarst or not, indicating the karstification degree has a more significant effect on hydraulic conductivity (K) when an epikarst is present while affecting effective porosity (φ) more noticeably in the absence of epikarst. The rainfall intensity affects the results of both experimental and numerical simulation most significantly. The percentage of discharge and solutes flowing from the slow reservoir (qS and msoil_S) have negative correlations with rainfall intensity, suggesting a greater influence on fast flow with increasing rainfall intensity.
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