Finance and economics: The economics of generosity The kindness of neighbours
A new paper asks why some Tanzanian farmers are more selfish than others.
In the semi-arid lowlands of Mufindi, in southern Tanzania, water is hard to come by.
Villagers rely on irrigation to grow maize, potatoes and spinach.
Informal and often woolly codes govern how much water each farmer diverts to their own fields, and how much they leave for their neighbours downstream.
Some farmers, naturally, turn out to be more grasping than others.
Economists typically see such decisions as irreducible: there is no accounting for individuals' values and preferences.
But a new study investigates why there is such variation in generosity among Mufindi's farmers.
The researchers asked other villagers to rank each farmer's social status on a scale of one to four.
Then they invited the farmers to take part in a game in which participants had to decide how much water they would take under different scenarios.
Participants were paid small sums, which varied according to how well they did in the game.
They received more money if they reaped a bigger harvest by taking more than their share of water, for instance, but less if the other villagers fined them for violating water-sharing norms.
In hypothetical times of scarcity, only high-status women shared the water fairly.
Low-status men and women would share fairly when water was plentiful, but were stingier when water was scarce.
High-status men hogged water at all times.
Rather than simply conclude that some farmers were more altruistic than others, however, the researchers split the participants into groups by status and gender to discuss the outcome.
Rich and powerful men, it turned out, were less worried about being greedy, either because the gains dwarfed any fine, or because they assumed their downstream neighbours would not dare complain.
One villager said that she had to keep quiet, since the person overusing the water was influential.
By contrast, another said, “Low-status people are not expected to break the rules.”
Women, even of high status, also seem inhibited.
The apparent generosity of women and the poor, in short, may not be the product of compassion, but of discrimination.