Lant Pritchett is like the lovable, crotchety uncle of development economics. He peppers colleagues, and policymakers, with annoying questions — specifically questions that are annoying because they hit on gaps in his targets’ worldview, gaps that they know about but are tempted to ignore.

Now teaching at the London School of Economics, Pritchett spent nearly three decades working for the World Bank. Throughout his career, he has advocated for a migration-first approach to development. Letting people move from poor countries to rich ones, he notes, is the most effective way we know of to make someone in a poor country better off. His research with Michael Clemens and Claudio Montenegro confirms this. Why, then, do most development groups, from the World Bank to USAID to philanthropies like the Gates Foundation, give the topic short shrift? Why not do everything in your power to increase migration flows from poor to rich nations?

The most common answer is “politics.” Not one to shrink from a fight, Pritchett teamed up with economist Rebekah Smith to start Labor Mobility Partnerships (LaMP) in 2020. The organization’s goal is to sidestep the most polarized and thorny topics in the immigration debate, like border security asylum rules and migrant detention, in favor of a laser focus on one goal: getting rich countries to allow more temporary work programs that people in poor countries can use, and setting up those programs to avoid exploitation.

That means looking beyond just the US, too. LaMP has worked on expanding access to short-term work opportunities in Canada, the European Union, and even the international cruise industry. In the US, it pushes to reform the H-2A and H-2B visa programs to allow workers in a greater number of fields, including more outside of agriculture. It rejects the idea that “low-skilled” immigrants count for less in favor of approaches that support migrants of all education levels.

This kind of deep engagement on migration policy is only one piece of Pritchett’s portfolio. He’s a major voice in broader debates about the future of global development. He’s an articulate critic of the turn toward randomized experiments in development, arguing that they both don’t tell us enough (because the programs they evaluate differ in impact across places and times) and don’t tackle big enough questions (because they can’t explain the ultimate reasons why some countries experience fast economic growth and others do not).

But migration and LaMP are at the core of how Pritchett thinks about these bigger questions, too. “Decades of well-intentioned development programs and aid initiatives cannot equal the benefit of permitting a person in a poor country to work in a wealthier, more productive one,” he wrote in a recent manifesto. “If they want to help the world’s poor, citizens of rich countries should understand that all the worthy development projects, antipoverty programs, and foreign aid to poor countries have an inconsequentially small effect compared with the benefits of just letting people move to the rich countries that need them and work for the going wage justified by their productivity.”