Plastic bag consumption during grocery shopping in Armenia was high, and there was little robust evidence on which policy interventions would actually shift behavior toward reusable alternatives.

We ran a six-month randomized field experiment, assigning 5,809 participants into seven groups and testing six different nudge designs, from environmental framing to financial bonuses, with and without the provision of reusable bags.

• A seven-arm randomized field design across real grocery stores
• Direct comparison of financial and environmental nudges
• Testing whether providing reusable bags amplified the effect of nudges
• Peer-reviewed academic publication of the results

Both financial bonuses and environmental nudges reduced plastic use, but the financial bonus was substantially more effective, and reusable bags combined with nudges outperformed nudges alone. The findings give Armenian policymakers concrete evidence on how to design plastic-reduction policy.