A bold experiment announced by the nonprofit GiveDirectly builds on growing evidence that simply giving people money can play a major role in mitigating the worst pains of extreme poverty, particularly among those living on $1 a day or less. Conventional wisdom says it’s too impractical, too costly, and unlikely to forge real change. But independent studies, including randomized control trials, indicate that one-off cash transfers can boost food consumption, improve the health of children, and help people and their small businesses establish long-term incomes. Despite concerns from skeptics, recipients don’t appear to buy unhealthy or frivolous items.

Of course, a basic income doesn’t solve all the big problems linked to extreme poverty. They don’t pay for public goods—things like roads, health clinics, or electricity grids—which are essential ingredients for successful market economies, but they do seem to expand people’s options in making their own life choices. GiveDirectly recently promised to go “next level” later this year, targeting more than 6,000 people in dozens of villages around Kenya, where poverty levels remain at over 40 percent. The program will provide participants with a basic income of around $0.75 to $1.10 per person per day for 10 years, and will partner with prominent independent researchers to assess the long-term effects through various metrics.

How much would it cost to provide a basic income to everyone living in extreme poverty? The answer depends on how ‘basic’ is defined.