on the Wikipedia article 'Stochastic matrix' http://en.m.wikipedia.org/wiki/Stochastic_matrix
there is a list of three possibilities. Either the stochastic matrix has a row sum of 1 , a
column sum of 1 or both. These possibilities are listed but the differences of these possiblites are not described. Even though Wikipedia is only a tertiary source: what are the differences between these possibilites? Obviously
a permutation matrix has row and column sum of 1. Is there an example
where a permutation matrix is used as a stochastic matrix?