Charges for plastic bags: Motivational and behavioral effects

Two field studies tested the effects of a charge for single-use plastic bags recently implemented in Buenos Aires City, Argentina. Study 1 showed a greater increase in consumers' own bag use after the charge was introduced in supermarkets where the policy was introduced, in comparison to control supermarkets where the charge was not introduced, or was introduced later in time. The effects were even stronger two months later. Study 2 analyzed factors underlying policy support and own bag use six month after the charge was introduced. Policy supporters highlighted environmental benefits of the charge, while opponents stressed the financial costs. Moreover, most consumers indicated that they carried their own bags to protect the environment, suggesting that intrinsic rather than extrinsic motivations caused behavioral changes. The theoretical and practical implications of the findings are discussed.