Case study of
#00090 Mandatory charges or levies on single-use carrier bags
California, United States
#00113
Implementer
California municipalities (bag bans); economic analysis by R. L. C. Taylor
Location
Description
California municipalities began banning single-use carryout bags from 2007 onward, with statewide policy following. A 2019 peer-reviewed economic analysis (Taylor, R. L. C., Journal of Environmental Economics and Management) found a substitution effect: households that lost access to free carryout bags purchased significantly more plastic trash bags — particularly small 4-gallon bin liners they had previously reused as bin liners. By weight, increased trash-bag purchases offset approximately 28% of the plastic eliminated by the bans. The net effect was still a plastic reduction, but materially smaller than the headline decline in carryout bags implied.
Metrics
1Lessons learned
- Banning one single-use item can push consumers toward purchasing a substitute plastic product (here, small bin liners), partially offsetting the intended reduction — the net effect must be measured against displaced consumption, not just the targeted item.
- Sales of small (~4-gallon) trash bags rose most sharply, because carryout bags had been serving double duty as free bin liners — regulators should anticipate this when scoping a bag policy.
- Lifecycle and leakage accounting is essential: the ~28% offset figure shows that headline carryout-bag reduction numbers overstate the true plastic savings if substitution is ignored.
Documented Jun 27, 2026