Laziness pays off: It's official

PARIS: People frustrated by the delayed arrival of a bus should take the lazy option and wait for it to show up rather than walk to their destination, mathematicians say.   

Number crunchers from Harvard University and the California Institute of Technology (Caltech) drew up a formula to calculate whether waiting or walking was the best option for those facing a sporadic bus service.   

Their equation has these variables: n, for the number of bus stops spaced along the bus route; d, for the distance along the bus route; Vw, being the bus speed; Vb, the walking speed; and p(t), being the probability in time that a bus will show up.   

Their verdict: stick around and wait for the bus at the first stop. If you set off walking, there is a comparatively greater risk that the bus will zoom past before you reach the next stop on the route.   

"The answer is intuitive: the optimal strategy is the laziest," the mathematicians say.   

Walking becomes the smarter option, though, if the distance to be travelled is less than a kilometre (five-eighths of a mile) and there is at least an hour between buses, the investigators told the British weekly New Scientist.   

The paper, by Justin Chen, Scott Kominers and Robert Sinnott, appears online in the open-access library of New York's Cornell University. New Scientist carries a report on it in next Saturday's issue.