Drawing on the general assumption that information is imperfect, this
article addresses three main issues. First, why do some migrants retur
n even though the intercountry wage differential does not reverse? And
who returns? Second, why do migrants who stay tend to share their hig
her earnings with others at origin, even in the absence of altruism or
of a need to establish an exchange relationship? And can the size of
these transfers be predicted? Third, what explains the earnings of mig
rants? Why do they often dominate the earnings of equivalent native-bo
rn workers even if differences in human capital are fully controlled f
or? The article suggests these answers. First, when informational symm
etry is reestablished, the low-skill workers, who are no longer pooled
with the high-skill workers, return. Second, migrants' remittances ar
e conceived as side-payments, made under asymmetric information, by hi
gh-skill migrant workers to low-skill workers, who, if they were to mi
grate, would erode the wages of the high-skill workers. And third, the
edge migrants have over native-born workers arises from the lower rec
ognition costs of partners to trade whose type is unknown.