Université de Lausanne
Faculté des
HEC
Département d'économétrie
et d'économie politique
Cahier de recherches économiques du DEEP No. 14.10
Adrian Bruhin, Lorenz Goette, Simon Haenni and Lingqing Jiang
Spillovers
of Prosocial Motivation: Evidence from an Intervention Study on Blood Donors
December 2014
Abstract
Spillovers of prosocial motivation are crucial for
the formation of social capital. They facilitate interactions among individuals
and create social multipliers that amplify the effects of policy interventions.
We conducted a large-scale intervention study among dyads of blood donors to
investigate whether social ties lead to motivational spillovers in the decision
to donate. The intervention is a randomized phone call making donors aware of
a current shortage of their blood type and serving us as an instrument for identifying
motivational spillovers. About 40% of a donor's motivation spills over to the
other donor, creating a significant social multiplier of 1.78.
JEL Classification: D03; C31; C36
Keywords: Social Interaction; Social Ties; Prosocial
Motivation; Blood Donation; Bivariate Probit