On Shopping Carts

Want to spend less money at the store? Don’t take a cart.

I had a very annoying experience at the grocery store this weekend. There was not one basket for me to use in the entire store. As it was busy, there weren’t many carts left either, and with all the carts on the go, the pace of the store ground to a halt. A clerk told me that all the baskets had been stolen (hmm, likely story, buddy!). So, for punishment for not thinking of my convenience, I decided I’d shop for only as many products as I could carry around the store, thereby spending a lot less money.

I used to do this all the time when living in the UK for my PhD. Without a car, I was limited to what I could carry home, so I’d make more frequent trips for less items at the store. But back in Toronto I almost always drive to the grocery store, and so it’s not really as big of a concern if I decide to throw a spontaneous purchase – or 3 – into my basket.  

Shopping carts were invited by Sylvan Goldman in 1937, originally consisting of a folding frame around a wire basket that was three times smaller than current standard grocery carts. They allowed for shoppers to pick up and purchase many more items at a time. And grocery stores absolutely know this – the bigger the cart, the more profit.

Martin Lindstrom, a marketing consultant and author of Brandwashed, described an experiment where they found that doubling the size of a shopping cart lead to a 40% increase in purchases.  Why? Quite simply because the shopping will stop once a basket has become full or too heavy.

With margins around only 1.5-2%, to make more money grocery stores need to get you to buy more stuff. Did we really need that extra stuff? Why are we falling for it?

Why do we fill our cart?

Context cues. Just like we tend to eat more when food is served on a bigger plate (because the big portion is taken as a cue for the appropriate amount to eat), so too might shopping carts act as cues on how much to buy.

Social norms. In a concise history of the shopping cart, the tale of Sylvan Goldman’s invention illustrates the power of social norms. Customers at his store were originally too proud to use the shopping cart. Only after hiring attractive men and women to push around his new invention did his customers adopt the practice. Seeing others use and fill up a cart has an impact on our behaviour because it indicates to us what’s acceptable practice in the grocery store.

Averaging bias. It might be hard for us to calculate the grand total spend of our entire cart. We might be averaging instead of summing – the good deals and the splurges. And, especially with a big cart, it might be hard to see all the items we tossed in there. Have you ever got to the checkout and been totally blown away with the total after adding everything up, even after you consciously picked out a number of sales items? Averaging bias might be at play.

So you’re saying I should always go for the basket, right? Oh no, but wait! Beware, carrying a basket might lead to making poorer decisions about what you buy. Research by Van den Bergh, Schmitt, and Warlop (2011) found that consumers carrying baskets were more likely to buy wasteful or unhealthy items simply because the sensation that comes from flexing when holding a basket is related to a sensation of instant gratification, in turn leading consumers to buy more items that offer the same sensation – like a candy bar.

A candy bar is okay once in a while (I like ice cream), I would still recommend a healthy, balanced diet. And not falling prey to spending more just because of pushing a cart around a store.

So, unless you are buying bulk – which, as a personal finance nerd, I think is very valid to get the most economical price of non-perishable products – stray from the cart. Benefit from the arm work out.

Not only will you be saving on your grocery bill by not buying things you don’t need or want, you will be reducing the amount of food waste. Not to pick on the States, but roughly 50% of produce is thrown away. That’s around 60 billion tons of waste, or $1,600 per year per family, just because shoppers did not accurately buy in line with their consumption needs. You could be saving $1,600 per year by shopping a bit more carefully and working on those biceps!