Scarcity and the bandwidth tax
The claim that not having enough money, time or food captures attention, so the mind tunnels on the shortage and has less left for everything else. Mullainathan and Shafir called the cost a bandwidth tax: forgetting, poor planning and short-term choices that come from preoccupation rather than character.
What drives it
Tunnelling gets the urgent bill paid by pushing everything else out of view. As a lens it moves the explanation for missed appointments and short-term choices away from laziness and towards load, which is useful even though the size of the effect is now in doubt.
How it shows
Work
Rent week shows at work: forgotten tasks, missed emails, a sharp reply to a small request. The person can solve the immediate money problem with real skill and still lose track of a deadline two weeks out.
Relationships
Plans with a partner get forgotten, a birthday slips, every conversation drifts back to the car, the overdraft or the late payment. Arguments about ‘not listening’ cluster in the days before payday.
Self
Notice whether the bill you can’t pay sits at the edge of every other thought, whether you reread the same paragraph three times, and whether choices you would call short-sighted on a good month make sense in the moment.
What tells it apart
Survival mode: Survival mode is a popular description of a whole life organised around getting through. The bandwidth claim is narrower: a specific shortage taking attention from other tasks, which should ease when the shortage does.
Present bias: Present bias is a standing preference for now over later that shows even when money is fine. Scarcity effects should come and go with the shortage, and are more likely visible before payday than after.
Scarcity: Cialdini’s scarcity principle is a persuasion tactic: things seem more valuable when they are rare or running out. The bandwidth idea is about what real shortage does to attention, not about how things are sold.
A test
Compare the same person’s forgetfulness and choices in the week before money comes in and the week after. A clear swing that tracks the shortage makes preoccupation more likely than a fixed trait.
Questions to carry
- In the days before the money came in, what did the person forget that they would normally remember?
- Which shortage is taking up my attention this week, and what have I stopped seeing because of it?
How strong the research is
mixed. Mani et al. (2013) reported that thinking about a large car repair bill lowered poorer people’s reasoning scores and that sugarcane farmers scored better after harvest than before, but the lab effect did not replicate in O’Donnell et al. (2021) or in a Colombian replication by González-Arango and colleagues, and Carvalho, Meier and Wang (2016) found no drop in cognitive performance before payday. The idea that money worry narrows attention is plausible, but the headline lab result is not established.
Where it comes from
Sendhil Mullainathan and Eldar Shafir, 2013 (Scarcity: Why Having Too Little Means So Much). Anandi Mani, Sendhil Mullainathan, Eldar Shafir and Jiaying Zhao, 2013 (Poverty impedes cognitive function, Science)