Abstract
We develop an ordinal theory of network formation, or - equivalently - one-sided manyto- many matching. We provide (i) relations between several solution concepts, (ii) sufficient conditions for their nonemptiness and (iii) an implementation result for the pairwise stable set. We closely follow Echenique and Oviedo (2006) and show that almost all the inclusion results for the solution sets proposed in the two-sided many-to-many matching model carry over to the one-sided many-to-many matching model under the assumption that preferences are (strongly) substitutable. Nonemptiness of solution sets will be established under a weak separability condition.