Three Essays on the generalizability of experimental results in economics

Although few economists today dismiss the use of the laboratory experiments, it would be a mistake to think that experimental methodology no longer represents a controversial issue in economics. One of the major criticisms is represented by the external validity of experimental data and concerns the transferability of results obtained in laboratory to the real world. The aim of this thesis is to tackle the issue of external validity focusing in particular on one aspect: the possible lack of representativeness of standard subjects pools usually used in economic research. The first experimental study compares the choices of undergraduates and subjects representative of population in different treatments and with different reward dimensions by exploiting the experimental design used by Pelligra and Stanca (2013) to investigate social preferences in a field experiment. Our results show that two samples follow a common behavioral pattern with the only exception of a significant difference in choices where self-interest may play a prominent role. In the second study we use a between-subjects design to compare the behavior of experienced and inexperienced subjects. We investigate whether the laboratory experience, built through repeated participation in experimental sessions, biases subjects’ behavior in a set of representative simple games used to study social preferences. Our main finding shows how subjects having a high level of experience in lab experiments do not behave in a significantly different way from novices.