Session-Effects in the Laboratory

Abstract

In experimental economics, where subjects participate in different sessions, observations across subjects of a given session might exhibit more correlation than observations across subjects in different sessions. The main goal of this paper is to clarify what are session-effects: what can cause them, what forms they can take, and what are the potential problems. It will be shown that standard solutions are at times inadequate, and that their properties are sometimes misunderstood.

Keywords: Session-effects, statistics, experiments, session averages, non-parametric tests

JEL Classification: C90, C12