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(credit: Martin Deutsch CC BY)

Too much perseverance

Does our tendency to keep going work in our favour?

“I’ve started so I’ll finish” is one of the first catchphrases that stuck in my mind when we moved to the UK many years ago. At the time, it was uttered pretty much weekly by Magnus Magnusson, the host of the Mastermind quiz programme, in which candidates need to answer general and specialist knowledge questions in quick succession during 2 minutes. Whenever he had begun reading out the last question at the moment the expiration signal is sounded, he continued doing so, and the candidate was then entitled to answer the question.

To me, it sounded not just fair but also entirely reasonable. Nice catchphrase, that also carries an exhortation to persevere: don’t give up. That, however, can lead to a cognitive error known as the sunk cost fallacy, observed particularly in business, where investment decisions regarding large, multi-year projects sometimes need to be revisited.

Avoiding waste

This curious persistence intrigues many behaviouralists, as the economics of such decisions are generally pretty clear-cut. What might explain hard-nosed business people’s and politicians’ dogged, inappropriate perseverance?

One possible factor may well be the urge to complete what we started, as voiced by Mr Magnusson, acting as a kind of default: unless you have a really good reason to stop, keep going. Another explanation may be our tendency to avoid losses. When you abandon a project, the resources spent so far are, to all intent and purpose, wasted. Even though, on balance and from a purely economic viewpoint, that might be the right choice, the emotion we experience with this loss is hard to ignore.

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“I’m bored stiff in Michigan, but I am wasting less money, so yay!” (photo: nonanet CC BY)

This is compellingly illustrated in a 1985 experiment by psychologists Hal Arkes and Catherine Blumer. Participants were presented with a hypothetical situation in which they purchase a ticket for a skiing weekend in Michigan for $100. Later they buy a $50 ticket for a skiing trip to Wisconsin (and the Wisconsin weekend is believed to be more enjoyable than the Michigan one). They then discover that both trips are on the same date, and they can neither obtain a refund, nor sell the tickets on: having spent a total of $150, they now have to choose one, and forego the other. The rational decision is to go to Wisconsin, as it is the more pleasant of the two. Yet the researchers found that less than half of their participants made that choice: by going to Michigan it was as if only $50, the price of the Wisconsin ticket, was ‘wasted’.

Material investment and loss is actually only part of the story: business and political leaders sometimes stake their reputation on a project. So, cancelling such a project may look, rightly or wrongly, like a loss of reputation, and that can be a major obstacle to doing what is economically right.

Also at home (and in the dovecote)

Have you ever, at the end of a meal in a restaurant when you’re ready to settle the bill, found there to be some wine left in the bottle — and felt strangely unable to leave it there? Did you fill up the glasses one last time, and quickly quaff the leftover? That is the sunk cost effect: if the waiter would offer you a free glass of wine with the bill (rather than the more customary mints), very few people would take it — yet because you paid for the wine, you feel the need to finish it.

And so it is for example for a book or a film that, halfway through, turn out to be a waste of time. But we paid good money for the book or the cinema ticket, and we’ve already invested an hour or more of our time. Quitting now means that time and that money is wasted — at least if we do not value the remaining reading or watching time that we could be doing something more pleasant. So it is too with eating what is on our plate, or even what is left in the pan: we bought the beans and potatoes, we cooked them, so we will bloody well eat them — even if we’re not really hungry anymore. (Bye bye, waistline.)

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“Plenty of food here, no need for red or green keys for me!” (photo: if winter ends CC BY)

Even animals exhibit similar behaviour. Thomas Zentall, a psychologist at the university of Kentucky, describes three experiments with pigeons trained to peck keys with a coloured light a certain number of times in order to obtain food (e.g. 30 times red, or 15 times green). After training, they presented the pigeons with a setup with three keys. In the first phase, the central key lit up red, and so the pigeons started pecking away to get their food. However, the experimenters switched off this key after 5, 10, 15, 20 or 25 pecks, and in the second phase lit up the keys on either side: one red, the other green. What would be the best choice for the pigeon? If it had already pecked on the central red key 20 or 25 times, it should choose the red key and complete the sequence with 10 or 5 pecks to get the reward. If it had only pecked the central red key 5 or 10 times, it should choose the green key and peck it 15 times to minimize the total number of pecks.

Yet they found the pigeons had a significant bias towards continuing with a red key and complete the sequence of 30, even if they could have obtained the food more quickly by choosing the green key. The birds exhibited a similar bias in the other two experiments.

Measured persistence

Is persisting an irrational tendency? Easy to ask, not so easy to answer. Who knows, the regret of leaving the wine in the bottle undrunk might outweigh the slight discomfort of drinking more wine than we wanted, and after the coffee. Maybe the feeling that we’re wasting more money going for the cheaper ski trip spoils the fact that it would be more pleasant, and so we’re ultimately better off reasoning that taking the expensive, less enjoyable weekend is the better option.

But perseverance does not always pay. So perhaps it is worth learning to spot when it is our autopilot making us continue something, and move the decision to a conscious level. Yours truly had an opportunity to practise this just a few days ago. On my plate was a succulent fillet steak, cooked and seasoned just right. But my appetite for meat has diminished over the years, and it was just too big for me. So, I figured I would not enjoy eating more steak than I really wanted, and I chose to leave about 20% of it on my plate. No regrets, and goodness me, did it feel liberating!

“I’ve started so I’ll finish” can be a pretty good rule of life, but it is not always so. The trick is to know when stopping pays more than persevering. The least we can do is ask ourselves the question.

Originally published at on July 5, 2019.

Thanks for reading this post — I hope you enjoyed it. Please do share it far and wide — there are handy Twitter and Facebook buttons nearby, and you can click here to share via LinkedIn, or simply copy and paste this link. See all my other posts (I publish one every week) here. Thank you!

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Accidental behavioural economist in search of wisdom. Uses insights from (behavioural) economics in organization development. On Twitter as @koenfucius

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