  Most doctors in the NRMP are matched to one of their most-preferred
internship programs. Since various surveys indicate similarities across
doctors' preferences, this suggests a puzzle. How can nearly everyone get a
position in a highly-desirable program when positions in each program are
scarce? We provide one possible explanation for this puzzle. We show that the
patterns observed in the NRMP data may be an artifact of the interview process
that precedes the match. Our analysis highlights the importance of interactions
occurring outside of a matching clearinghouse for resulting outcomes, and casts
doubts on analysis of clearinghouses that take reported preferences at face
value.
