Rich people can afford to buy more sleep than poor people

In Rich do not rise early: spatio-temporal patterns in the mobility networks of different socio-economic classes, a group of transportation engineers analyze an open data-set about the commutes of people in the Colombian cities of Medellín and Manizales, concluding that the rich and the poor commute the furthest distances, but that the rich have much shorter commutes, thanks to private transport and superior routing, which translates to substantially more sleep for the wealthy.

Sleep deprivation is well-understood to cause cognitive impairment and physical illness. Poor commuters in the study leave their homes later, and return later, than rich ones, suggesting that their livelihoods are at odds with their ability to sleep.

In addition to these spatial patterns, the authors are also interested in temporal patterns. So they look at the times of day when people in the different groups are likely to travel. The researchers were surprised to find that the timing of movement is also closely linked to socioeconomic status. They saw that as socioeconomic class increases, every morning's peak transit time moved to later and later in the day. So people with the lowest status had peak morning transit times around 5AM or 6AM, whereas those with higher incomes didn’t peak until nearly 7AM.

The authors conclude that higher socioeconomic status allows people to buy more time to sleep or engage in leisure activities in the morning, so they can leave their homes later. In contrast, people with less economic capital tend to leave their homes earlier because they utilize slower and less reliable modes of transit, such as walking or taking public buses.

Though this study was meant to probe the importance of socioeconomic status in human mobility, it also shows another important point: wealth allows people to buy a more comfortable life. This is sobering because it suggests that possessing wealth is a self-perpetuating state. The poor, who spend more time stuck in transit, have less opportunity to increase their income. The poor may also be unable to afford the luxury of sufficient sleep, which influences their ability to pull themselves out of poverty.

Rich do not rise early: spatio-temporal patterns in the mobility networks of different socio-economic classes [Laura Lotero, Rafael G. Hurtado, Luis Mario Floría, Jesús Gómez-Gardeñes/Royal Society Open Science]

The wealthy commute later, get to take more direct routes [Roheeni Saxena/Ars Technica]

(Image: Four-poster bed - Casa Loma, Thomas Quine, CC-BY)