Are Pro-environment Behaviours Substitutes or Complements? Evidence from the Field

This paper uses a field experiment among adolescents in India to study how interventions to increase one pro-environment activity (namely, recycling single-use plastic carry bags), spill over to other pro-environment activities. I show using lab and field experiments combined with survey data that (i) providing information on the need to recycle does not change recycling behaviour, whereas (ii) providing incentives along with the information leads to higher recycling. There is a positive spillover from the incentive treatment to other pro-environment activities. This positive spillover is observed among subjects who respond to the incentives and increase recycling. Notably, the positive spillover is also observed among those in this treatment who do not respond to the incentives and do not change recycling behaviour. This provides evidence for complementarities among pro-environment behaviours and suggests that interventions may have unaccounted positive effects on non-target environment behaviours.