Walk into a Brazilian urban supermarket and your are highly likely to walk out with purchases carried in small, thin plastic bags. Buying a lot of things? Shop staff increase the number of small bags – rather than provide larger carrying alternatives. Heavier items? Wrapped in two bags. Larger bags are available but are the exception rather than the norm.

There are four possible reasons I can think of for this standardisation: they are commonly used for collecting household waste and are of a size that will fit apartment block waste disposal chutes; larger bags are unsuitable for waste disposal because bio-waste quickly starts to hum in the tropical heat – smaller bags trigger residents to empty their waste almost on a daily basis; they’re cheap; and possibly the weakest argument – that Brazilians prefer to shop smaller amounts more frequently – taking advantage of the abundant availability of fresh produce. Any other reasons you can think of?.

Why are the factors that nudge a country’s inhabitants into adopting a particular type of carrying container? What does it take to shift to alternative carrying containers?