經濟與管理論叢(Journal of Economics and Management), 2013, Vol. 9, No. 2, xx-xx Adverse Selection and Moral Hazard in Joint-Liability Loan Contracts: Evidence from an Artefactual Field Experiment Giorgia Barboni Institute of Economics, Sant'Anna School of Advanced Studies Alessandra Cassar 1 Department of Economics, University of San Francisco, CA Arturo Rodriguez Trejo Department of Economics, University of San Francisco, CA Bruce Wydick Department of Economics, University of San Francisco, CA We design an artefactual field experiment to study the relationship between joint- liability lending and adverse selection, moral hazard and risk preferences. While theories concerning joint-liability lending have highlighted its ability to mitigate adverse selection in credit transactions, our experimental results indicate that joint-liability lending may actually induce problems of adverse selection. The results of our experiment, carried on in partnership with a Bolivian microlender, show that borrowers exogenously endowed with a risky project are disproportionately likely to choose jointly-liability contracts over individually-liable contracts. This behavior does not 1 Institute of Economics, LEM, Sant'Anna School of Advanced Studies, e-mail: giorgia.barboni@gmail.com. We would like to thank Eliana Zeballos for assistance in carrying out the experimental work, Travis Lybbert for use of the University of California at Davis mobile experimental laboratory, and the University of San Francisco for financial support. We thank seminar participants at the London School of Economics and at the Second European Research Conference on Microfinance, and two anonymous referees for their comments. We would like to especially recognize the support of Porvenir for allowing its clients to be part of this study.