  In assignment problems, the rank distribution of assigned objects is often
used to evaluate match quality. Rank-minimizing (RM) mechanisms directly
optimize for average rank. While appealing, a drawback is RM mechanisms are not
strategyproof. This paper investigates whether RM satisfies the weaker
incentive notion of non-obvious manipulability (NOM, Troyan and Morrill, 2020).
I show any RM mechanism with full support - placing positive probability on all
rank-minimizing allocations - is NOM. In particular, uniform randomization
satisfies this condition. Without full support, whether an RM mechanism is NOM
or not depends on the details of the selection rule.
