Morrison’s Fails Chesterton’s Fence With The 20p Paper Bag


The supermarket chain, Morrison’s, has decided that what we all really need is a 20 pence paper bag to take our shopping home with us. This might not be the wisest business decision ever as it fails a pretty basic logical test known as Chesterton’s Fence. Why did we start using plastic bags? Because they were better than the paper ones that went before presumably. So, the benefit of ditching the plastic for the paper is?

Morrisons is to trial the launch of large paper bags for groceries at supermarket check-outs and is raising the price of its plastic bags by 50%. The supermarket will now charge 15p instead of 10p for its cheapest standard plastic bag, while testing out US-style paper grocery bags with handles costing 20p.

Well, yes, we might want to think a little about the environmental impact of that. It’s not always true that what we’re told uses less resources does use fewer resources:

We can even construct a little spectrum here. How many times do we need to reuse a bag for it to have as little resource use – and thus environmental effect – as just the one use of those thin single use plastic ones? Obviously enough, the single use that we’re told not to use has a value of one here. The bag for life must be reused 35 times. A bag for life from recycled plastic 84 times. A paper bag must be reused 43 times – yes, paper. A cotton bag 7,100 times and an organic cotton? 20,000. Which is the environmentally friendly option here? Clearly and obviously the one that everyone insists we must not use. So much for fashionable nostrums then.

It’s also true that we did in fact know this. The Environment Agency released a paper saying much of this in 2011. A Danish official paper confirmed it in 2018. Even a paper purporting to support the change states that a bag must be used for five years to be truly as environmentally friendly. Still, we are told that more must be done to stop us from using the least damaging type of bag.

We’ve even got a useful little signal here. That they want to charge 20p for the paper and 10p for the plastic does at least imply that the plastic uses half the resources….