•Predicts the environmental and economic performance of policy instruments to promote plastic recycling.•Combines equilibrium model (top-down) with techno-economic and life cycle assessment (bottom-up).•Policy instruments that do not target a specific technology are more likely to increase thermochemical recycling than mechanical recycling.•Policy instruments should focus on environmental outcomes rather than increasing recycling rates.•Future research should include geographical considerations and asses other circular economy strategies. The objective of this paper is to examine the recycling rates for mechanical and thermochemical recycling of postconsumer polyethylene flexible packaging after the implementation of different policy instruments. The study uses a supply chain equilibrium model that incorporates market data and techno-economic assessments to simulate market equilibrium. It combines this with a life cycle assessment to explore the environmental implications of implementing different policy instruments. The results show that instruments that do not target a specific technology are more likely to increase thermochemical recycling than mechanical recycling. Furthermore, a higher recycling rate is not equivalent to a better environmental outcome. An increased collection target that ensures a supply of plastic waste would increase the overall recycling rates the most. A recycled content standard for mechanical recycling would lead to the highest increase in mechanical recycling, with top results for environmental indicators, but low results for economic indicators. Display omitted