My question is how does that transfer to other environments? Do the results at $22 a month in Kenya translate to the results at $1000 a month in the US? There's a lot more interesting things to buy with a $1000 in New York than there is with $22 in a village in Kenya. It's also a different society, different people. Maybe more religious, etc.
Just throwing out a stupid idea: Kenya's population is 47 million. To give all of them $22 a month (ignoring age cutoffs), unless I'm doing the math wrong would be just under $13 billion a year. If some really wealthy people really want to test this, it's not impossible.
Unlike the article's repeated claim that this is the "greatest myth" (it's really annoying how news articles editorialize with untestable statements like that), the biggest issue is still cost. How do you realistically put together and pay for a program that can become policy in the US? It's the 3 trillion dollar question.