Nonna Mayer introduces the topic of today’s seminar: field experiments and the measure of racial discrimination. Field experiments are commonly used to measure discrimination in non-interactional situations. A host of “correspondence studies” (testings) examine differences in callback rates to job applications according to the origin or religion of the applicant. But they rarely consider discrimination in everyday social interactions, despite the psychological distress such discrimination is known to generate. Martin Aranguren (Sciences Po, CRIS) took on the challenge of investigating everyday discrimination in urban public places, on the basis of field experiments. He speaks about a large-scale field experiment that he recently conducted on racial discrimination in the streets of Paris, exploring the help people are ready to give to passers-by. His research is discussed by Morgane Laouenan (CNRS, Centre d’économie de la Sorbonne -Paris 1 – Sorbonne, IRD/LIEPP-Sciences Po), a specialist of racial and gender discrimination, and by Achim Edelmann (Sciences Po, Medialab), a specialist of the sociology of culture, social networks, and computational methods.