Programming for Experimental Economics: Introducing CORAL - a lightweight framework for experimental economic experiments

The field of experimental economics is past its 50th anniversary and is celebrating its 2nd Nobel prize winner. By far the largest number of economic experiments are now conducted in computer labs, although there is a wide array of settings, ranging from pen-and-paper to elaborate field settings. The controlled environment of the computer lab remains a strong foothold for experimental research. On top of the high level of control, including the standardisation of recruitment protocol and software used, the ease of data collection singles out the lab environment as a key instrument for the testing of economic theory and market mechanics. A number of tools and procedures have developed over the recent decades shaping how experiments are conducted. Z-tree (Fischbacher, 2007) has been established as the quasi-standard tool to conduct experiments. This paper introduces a novel view on how to approach programming for experiments, specifically it introduces a number of innovations from professional software development into the programming of economic experiments. Finally the lightweight experimental software framework CORAL will be introduced.