Banning Plastic Bags- effective or feel-good measure

Governments around the world have headed demands from their citizenry and adopted bans on plastic bags. From Kenya to California, Europe to Eurasia, these bans have variation in the details of their legislation, but the basic framework is always the same- no more free single-use, thin plastic bags available at the checkout counter. After seeing images of marine life and landscaped chocked by thousands of bags, it’s easy to understand why there is such an outcry to “ban the bag”. But have these measures been successful? From the first ban some 30 years ago (see a history of the plastic bag here), opponents of bans have seeded doubt and claimed they would be ineffective and, in come cases, even have more harmful effects than continuing with the status quo.

Luckily, enough time has passed for researchers to look at and measure the effects of these bans to give us an unbiased answer, free of speculation and hand waving. I wish I could tell you that the answer was either a straight forward yes or no but, as is so often the case in the real world, the answer is messy and complicated.

Put on your blinders and declare success!

Politicians love this one. First, they gain popularity among voters by backing a ban then they declare success after the legislation has passed. Here I don’t mean to demean politicians (too much). Again, it’s hard not to want to ban the bag after seeing the problems they can cause, so I’m sure their intentions are good. Then, passing legislation isn’t easy work so they are motivated, both consciously and unconsciously, to believe that what they have done has been effective.

The fault comes when they declare success using narrow and or singular criteria. For example, if the only criterion for success is a reduction in free single-use plastic bag handed out at the checkout stand, then they are not wrong. Indeed, numerous studies have shown this to be true. What this oversimplified conclusion lacks is scope. If the free single-use bag is gone, what has it been replaced with?

Economists call it leakage

This time it’s not a gastrointestinal issue. When economists use the term “leakage” they are referring to increased consumption of products that are similar to one that has just come under regulation. In this case, It was only the free thin plastic bags given at checkout that were banned You can still buy plastic bags of all types, including thin ones! Could there be leakage?

That’s exactly what University of Sydney Economist, Rebecca Taylor, found. Sales for small, medium, and tall plastic bags, those used as trash bin liners, increased by 120% 64%, 6% respectively in California supermarkets after their ban went into effect. When questioned about their purchases, it was common for customers to say that before the ban they would reuse their shopping bags as trash bin liners. Very few of the calculations used to predict the effect of bag ban legislation took this type of leakage into account. Not only are thin plastic bags still out there but now they are truly only single-use, while previously they carried our groceries then lined our trash bins.

Of course, this now begs the question, how has the demand for a bag to carry groceries leaked where the free ones are banned? The answer here is one we are far more familiar with. By and large, our bags have been replaced with some more durable version. Often we are presented with a thicker plastic option for purchase at the checkout stand, or various other cloth tote bag type options. This leakage was predicted and opponents of bans were quick to point out its effects.

First, there’s the thicker plastic bag. Using a life cycle assessment (LCA), which is preferred by greenies since it takes into account everything from raw material extraction to disposal or recovery, it was determined that a thick polyethylene bag needs to be reused 50-100 times before it’s a greener option than the old free thin bag. Cotton bags are even worse, needing to be reused an astounding 153 times.

Seems like something’s missing

Indeed, something is missing, and for many people, it’s a big one- the reduction of plastic bags in the environment. It turns out that measuring the effects of plastic bags in the environment isn’t easy to quantify so it gets passed over in academic studies in favor of more friendly metrics. Who can say how many turtles didn’t choke to death due to your state’s ban and exactly how much is that worth anyway? What is the value of a landscape not filled with plastic tumbleweeds? Tough to say. For this article, I was unable to find any reliable research that points to a reduction of direct environmental pollution by plastic bags, but it’s hard to believe there isn’t some positive effect.

The water is muddied but not our resolve

In the end, it’s nice to know that enough people care to try to do something. Unfortunately, like so many issues in life, the solution isn’t as simple as we may wish it to be. We something we hate, we advocate to see it banned, and that makes us feel good. But this fight to save our planet is going to take more than knee jerk feel-good measures. We all must never stop asking the hard questions, even of those things that make us feel nice, to pursue effective evidence-based policy and eventually, we will prevail.