I am optimistic enough about this that I am willing to make a prediction. By 2035, there will be almost no poor countries left in the world. (I mean by our current definition of poor.)2 Almost all countries will be what we now call lower-middle income or richer. Countries will learn from their most productive neighbors and benefit from innovations like new vaccines, better seeds, and the digital revolution. Their labor forces, buoyed by expanded education, will attract new investments.

A few countries will be held back by war, politics (North Korea, barring a big change there), or geography (landlocked nations in central Africa). And inequality will still be a problem: There will be poor people in every region.

But most of them will live in countries that are self-sufficient. Every nation in South America, Asia, and Central America (with the possible exception of Haiti), and most in coastal Africa, will have joined the ranks of today’s middle-income nations. More than 70 percent of countries will have a higher per-person income than China does today. Nearly 90 percent will have a higher income than India does today.

It will be a remarkable achievement. When I was born, most countries in the world were poor. In the next two decades, desperately poor countries will become the exception rather than the rule. Billions of people will have been lifted out of extreme poverty. The idea that this will happen within my lifetime is simply amazing to me.Some people will say that helping almost every country develop to middle-income status will not solve all the world’s problems and will even exacerbate some. It is true that we’ll need to develop cheaper, cleaner sources of energy to keep all this growth from making the climate and environment worse. We will also need to solve the problems that come with affluence, like higher rates of diabetes. However, as more people are educated, they will contribute to solving these problems. Bringing the development agenda near to completion will do more to improve human lives than anything else we do.