When people are called upon to rally around a “public good” such as conserving water, they are more likely to do so if they believe they are working together to achieve a common goal.
As of February 2018, Cape Town’s residents must cut their water consumption drastically, as the region’s dams run critically low following the worst drought in a century.
This can give people an incentive to free-ride on others’ efforts, where some will benefit from the resource, while contributing nothing to its conservation.
Our team at the Environmental Policy Research Unit (EPRU) worked with the City to run a series of “behavioural nudges” to encourage voluntarily water-wise behaviour among residents – for example, sending targeted messages comparing a household’s consumption to the average consumption in their neighbourhood.
Remarkably, then, even before the new recommended use of 6 kilolitres per household came into effect in February 2018, 30% of households were already reaching this target.
Households across Cape Town have reduced their water use dramatically in the past four years, co-operating to meet the City’s monthly targets.
But in recent months, as restrictions have tightened, we see a dramatic change in consumption, particularly among the higher income households, while lower income groups, who don’t have as much scope to cut their use further, have always had rather low levels of water consumption.
The graph below shows how, by this January, wealthier households have reduced their consumption to the levels of poorer households.
In four years, wealthier households in Cape Town have reduced their water usage to that of lower income homes, who have much less scope for reducing an already low consumption level.
It’s crucial, therefore, that we signal to citizens that their efforts are working: that we are co-operating, and that our communal efforts are actually working to push back Day Zero.