[gottorf]

I believe there have been a few studies that studied localities (in different parts of the world) that banned plastic bags, and they've all had either zero net effect on plastic usage or it actually increased.

Anecdotally, 100% of grocery-store plastic bags I get are reused as trash bags and doggy poop bags. Same for most other people I know. Very few actually get thrown away after one use. And as it turns out, people in areas where such bags are banned, they buy other kinds of plastic bags to use for those purposes.