Here in the UK a law was passed requiring shops to charge 0.05GBP for each plastic bag, and it successfully reduced the number of bags used: "Our data indicate

Here in the UK a law was passed requiring shops to charge 0.05GBP for each plastic bag, and it successfully reduced the number of bags used: "Our data indicates that the 7 main retailers issued around 83% fewer bags (over 6 billion bags fewer) in 2016 to 2017 compared to the calendar year 2014" https://www.gov.uk/government/publications/carrier-bag-charge-summary-of-data-in-england/single-use-plastic-carrier-bags-charge-data-in-england-for-2016-to-2017 https://www.gov.uk/government/publications/carrier-bag-charg... The bags are called "single-use", but the shops also changed the bags to use thicker plastic (maybe so people feel they're getting their money's worth), and now they are much better for re-use too.