@unpublished{publication-5642,
	author={Fehr, Ernst and Schmidt, Klaus M},
	institution={University of Zurich},
	issn={1424-0459},
	number={No. 191},
	series={Working paper series / Institute for Empirical Research in Economics},
	title={Fairness and Incentives in a Multi-Task Principal-Agent Model},
	year=2004,
}