Can paying poor nations to admit refugees solve the mass migration puzzle?

The deeper analysis of why immigration policy is so hard to fix deserves close attention

Much of the commentary about Michael Kremer, named this week as one of three winners of the Nobel Memorial Prize in Economic Sciences, has justifiably celebrated his pioneering work in studying poverty — even now, many of us believe, the planet’s greatest moral challenge. But an important 2011 Kremer paper, overlooked in the celebration, helps to shed light on another great challenge of our day: refugee policy.

His work helps explain the immigration pressures that have been roiling politics around the world. In the wake of the disaster in Syria and other crises, refugees have flooded Europe. Nationalist parties have responded