How Laws Affect Behaviour

43 Pages Posted: 6 Nov 2008

See all articles by Roberto Galbiati

Roberto Galbiati

Department of Economics, Sciences Po-CNRS

Pietro Vertova

Bocconi University

Date Written: November 5, 2008


Laws and other formal rules are 'obligations backed by incentives'. We explore how laws work and affect behavior. Our analysis is based on a series of modified experimental public good games designed to isolate the impact of exogenously requested minimum contributions (obligations) from those of marginal incentives backing them. We find that obligations have a sizeable effect on cooperative behaviour even in absence of incentives. When non-binding incentives are introduced, requested contributions strongly sustain cooperation. Therefore, in contrast with cases in which incentives crowd out cooperative behaviour, in our experiments obligations and incentives are complements, jointly supporting high levels of contributions. Our results are consistent with the view that conformity to a rule is perceived as an obligation when it is backed by a system of incentives whose role in this case is not to modify the payoffs from material actions, but to give salience to the content of the rule. Moreover, we find that variations in obligations affect behaviour even when incentives are held constant. Finally, the effect of obligations on behaviour depends both on their impact on people's beliefs about others' contributions and on a direct effect of obligations on individuals' preferences for cooperation.

Keywords: Beliefs, Formal Rules, Incentives, Laws, Obligations, Preferences, Public Good Games

JEL Classification: C91, C92, H26, H41, K40

Suggested Citation

Galbiati, Roberto and Vertova, Pietro, How Laws Affect Behaviour (November 5, 2008). Available at SSRN: or

Roberto Galbiati (Contact Author)

Department of Economics, Sciences Po-CNRS ( email )

28 rue des saints peres
Paris, 75007

Pietro Vertova

Bocconi University ( email )

Via Sarfatti, 25
Milan, MI 20136

Do you have a job opening that you would like to promote on SSRN?

Paper statistics

Abstract Views
PlumX Metrics