Ma (1996) studied the random order mechanism, a matching mechanism suggested
by Roth and Vande Vate (1990) for marriage markets. By means of an example he showed that
the random order mechanism does not always reach all stable matchings. Although Ma's (1996)
result is true, we show that the probability distribution he presented { and therefore the proof
of his Claim 2 { is not correct. The mistake in the calculations by Ma (1996) is due to the
fact that even though the example looks very symmetric, some of the calculations are not as
\symmetric." JEL classi¯cation: C78
Peer reviewed