Is the ban effective?

Depends on how you look at it. After the city ordinance barring large-store retailers from dispensing thin plastic bags went into effect last August, some businesses, such as grocer Mariano’s, moved to paper. But many others, including Jewel-Osco, Target, and Walgreens, seized on an allowable option meant to encourage reuse: switching to new plastic bags that are at least 2.25 mils—four times thicker than the old ones.

How does that play out for stores?

According to an example provided by the Illinois Retail Merchants Association, one independent Chicago grocer gave out 20,000 plastic bags a week before the ban. After: 10,500. (That decrease, the store reports, is less about reuse and more about fewer customers demanding double-bagging.) But because the bags are thicker, that nets out to twice as much plastic usage as before.

What’s the impact on garbage?

“You can tell visually that there are fewer bags in the stream,” says Tomas Vujovic, area recycling director at Waste Management, which handles Chicago’s garbage removal. Ideally, he wouldn’t see any: Plastic bags clog the sorting machines. Workers spend almost 20 percent of their time pulling them out. But that’s down from 25 percent before the ban went into effect, Vujovic points out.

How are paper bags faring?

Mariano’s gave out 50 percent more over the past 12 months, but CEO Bob Mariano says that increase is lower than expected. (Paper bags, by the way, aren’t exactly eco-saviors: A British study found that they need to be reused at least three times to ensure lower global warming impact than a one-use plastic bag.) Mariano’s also sold 200,000 of its reusable canvas and superthick plastic totes ($1 to $7 each) in the past year, up from a negligible amount.

What’s next?

Today, smaller stores (less than 10,000 square feet) must start complying with the ordinance, too. Meanwhile, Alderman Proco Joe Moreno and others are lobbying to increase the minimum plastic thickness of totes to 10 mils, hoping that the additional cost to stores will finally make those bags too expensive to hand out willy-nilly for free.