Bill Gates wants to give the poor chickens. What they need is cash.

You’ve said that a family that receives five hens could eventually earn $1,000 annually, assuming a per-bird price of $5. But would that still be true when a third of your neighbors are in the same business? As supply goes up, I’d expect the price and profits to come down. And moving to an economy in which 30 percent of rural Africans sell chickens is a humongous increase in supply.

.. This brings me back to cash. “Give a man a start-up grant,” I say, “and he can buy chickens, or fishing lessons, or open a shop.” Cash is more versatile than livestock or skills. And time and again, the research has shown that the poor make good investment choices when given the opportunity. I propose we give impoverished Africans cash, and to let Heifer offer chickens and services for sale.

.. The poor generally have good investment opportunities but little access to capital. If you give them capital, such as cash or tools — they tend to invest it, work more (not less) and raise their earnings. Especially the young

.. It would be straightforward to run a study with a few thousand people in six countries, and eight or 12 variations, to understand which combination works best, where, and with whom. To me that answer is the best investment we could make to fight world poverty.

.. When it comes to ending poverty, you could tell people that we don’t know the answer yet, but it is answerable. You could say: “The future is randomized trials testing different poverty programs against one another in many countries, focusing on cost-effectiveness.” That sentence is short enough for a tweet.

How digging half moons helps farmers in Burkina Faso

In Burkina Faso, rainfall is erratic, and without techniques like these, rain from a downpour would roll off the parched soil, leaving little nourishment for crops.

But where half moons are dug, the water is held in place, giving it a chance to seep into the soil, where it will better nourish crops.

When Tiendrébeogo first heard about half-moons, he doubted they would work.

“But through our experience, we are delighted to use the new practices because everything went well and it did not cost any extra money,” he says. Farmers don’t need chemical inputs because they can use organic fertilizers from their livestock.

Facebook’s Gateway Drug

Consider the role of “identity services,” the mesh of publicly issued identifications that has traditionally meant things like driver’s licenses and Social Security numbers, but has come to include things like Facebook accounts. In a short essay outlining the vision behind Internet.org, Mr. Zuckerberg says one of its goals is to offer credit and identity infrastructure “that is still nascent in many developing countries.” Such services might be of some help in developing countries. But is Facebook the best entity to provide them?