@unpublished{publication-5512,
	author={Stutzer, Alois and G{\"o}tte, Lorenz and Zehnder, Michael},
	institution={University of Zurich},
	issn={1424-0459},
	number={No. 279},
	series={Working paper series / Institute for Empirical Research in Economics},
	title={Active Decisions and Pro-social Behavior: A Field Experiment on Blood Donation},
	year=2006,
}