In Norway we went the other way - our grocery bags are so thick and sturdy that they're reused as garbage bags for 95%+ of households instead of garbage bags. Our garbage looks like this (the blue bags are free government provided bags for plastic recycling): https://i.imgur.com/WbAsG3y.jpg

Environmental organizations here actually complained about the plastic bag tax because they feared it would lead to people buying garbage bag rolls instead of reusing the grocery bags for their garbage.

Anecdotally I'd say it also makes our garbage system "less messy" than systems that depends on bigger thrash bags - a hole in a large flimsy thrash bag is more likely and has a bigger negative effect than one in a small sturdy one.

Very good point, really good to hear the new bags aren't weighing in at too much more than the old ones! Also worth noting that the heavier bags are better quality and so will last longer. Combine this with the fact that because bags are no longer a 'free commodity', I think people will tend to assign value to them and hence re-use them much more than before.

I think it's probably better than that though, because while some supermarkets have switched to using heavier bags, some are still using the lightweight ones.

The mass measurement is good to know; however, the lighter bags also take to the air and land in trees, the water, etc., a surprisingly large effect in the Windy City (yes I know it's not called that because of actual wind :-) ). This effect has almost disappeared in my neighborhood with the new tax in place.

> the old ones

Charging for bags was commonplace in the UK in the 80's ... how long have you been keeping these for??

Tesco/Sainsbury's (two of the big supermarkets) now only supply "bag for life"s (thicker plastic) and do not have any of the 'normal', thin, carrier bags. That's happened within the last year.

I now have loads of "bags for life" because sometimes you forget to bring one, don't bring enough or shop on a whim.