In reality, they argue, people’s income can be unpredictable and sporadic -farmers, for instance, may earn all their money just once or twice a year after harvest time. Also, the idea of a subsistence income risks painting an overly simplistic portrait of poor people’s lives. As the work of economists Abhijit Banerjee and Esther Duflo has shown, the poor - just like the wealthy - take active decisions on how to spend their incomes, sometimes sacrificing nutrition in order to save for celebrations, for example.