Much of the methodological discussion around experiments in economics and other social sciences is framed in terms of the notions of internal and external validity. The standard view is that internal validity and external validity stand in a relationship best described as a _trade-off_. However, it is also commonly held that internal validity is a _prerequisite_ to external validity. This article addresses the problem of the compatibility of these two ideas and analyzes critically the standard arguments about the conditions under (...) which a trade-off between internal and external validity arises. Our argument stands against common associations of internal validity and external validity with the distinction between field and laboratory experiments and assesses critically the arguments that link the artificiality of experimental settings done in the laboratory with the purported trade-off between internal and external validity. We conclude that the idea of a trade-off or tension between internal and external validity seems, upon analysis, far less cogent than its intuitive attractiveness may lead us to think at first sight. (shrink)

We present an experiment designed to investigate three different mechanisms to achieve impartiality in distributive justice. We consider a first-person procedure, inspired by the Rawlsian veil of ignorance, and two third-party procedures, an involved spectator and a detached observer. First-person veiled stakeholders and involved spectators are affected by an initially unfair distribution that, in the stakeholders’ case, is to be redressed. We find substantial differences in the redressing task. Detached observers propose significantly fairer redistributions than veiled stakeholders or involved spectators. (...) Risk preferences partly explain why veiled stakeholders propose less egalitarian redistributions. Surprisingly, involved spectators, who are informed about their position in society, tend to favour stakeholders holding the same position as they do after the initial distribution. (shrink)

We perform an experimental investigation using a dictator game in which individuals must make a moral decision —to give or not to give an amount of money to poor people in the Third World. A questionnaire in which the subjects are asked about the reasons for their decision shows that, at least in this case, moral motivations carry a heavy weight in the decision: the majority of dictators give the money for reasons of a consequentialist nature. Based on the results (...) presented here and of other analogous experiments, we conclude that dicator behavior can be understood in terms of moral distance rather than social distance and that it systematically deviates from the egoism assumption in economic models and game theory. (shrink)

The article identifies a latent debate in the recent literature on the role and worth of experiments in economics and other social sciences concerning the relationship between the external and the internal validity of experimental designs. Our work identifies two incompatible views regarding the relationship between internal and external validity of experiments. While in the methodological literature references to the idea that there is a trade-off between the internal and external validity of experiments abound, this view coexists with the position (...) stating that internal validity is rather a prerequisite of external validity. By identifying the contours of this implicit debate in the recent methodological literature around the use of experiments in the social sciences we call attention upon a series of insufficiently conceptualized issues regarding the central notions of internal and external validity and we question the standard view positing a trade-off between the two. This article stands against common associations of internal validity and external validity with the distinction between field and laboratory experiments and assesses critically the arguments that link the artificiality of experimental settings done in the laboratory with the purported trade-off between internal and external validity. (shrink)