A straightforward extension of the McNemar test for paired binary data
yields an exact test for the equality of the limiting marginal distri
butions for bivariate binary Markov chains. The exact distribution of
the test statistics under the null hypothesis of equal marginals depen
ds on the classical cell occupancy statistics for the Bose-Einstein mo
del. Exact p-values are computed for the one-sided test, and the mean
and variance of the test statistic are found. The power of the Markov-
McNemar test is found to be close to the power of the classical McNema
r test for independent paired observations when the independence assum
ption holds. The method is applied to the comparison of ribosomal DNA
sequences.