Seeing some of comments about price.. just thought I can put more info here since that's where I'm from and some points are not mentioned, especially the previous plastic reduction effort by Taiwan started in 2002.

In 2002, the restriction on plastic bags that are thinner than 0.06mm was imposed to all stores, but it was not a complete ban. Stores that offer plastic bags thicker than 0.06mm need to charge customers. The idea behind thicker bag is reusability. Two types of responses from stores: Stores started providing thinner bag as long as they are bio-degradable (Link 1), or they provide thicker bag as long as customers are charged. Customer's response: Since 2002, 71.7 reduction in plastic bag use in supermarkets, and 43.4 reduction in plastic bag use in stores. (Link 2, Link 3)

And just a side note, Taipei started being more aggressive since 2000 by charging garbage bags. You have to purchase government issued garbage bags if you want to throw your garbage out of your house. (Mentioned in link 4)

Some links are in Chinese

Link 1: http://e-info.org.tw/node/202363

Link 2: http://www.epochtimes.com.tw/n176732/%E6%93%B4%E5%A4%A7%E9%9...

Link 3: Similar to link 2 with different stats https://www.csmonitor.com/2004/0615/p07s02-woap.html

Link 4: https://www.taiwannews.com.tw/en/news/3134910