Why do co-ops dominate in certain markets rather than more-conventional enterprises?
For example, the US dairy processing market seems to be dominated co-ops like Land'O Lakes and Dairy Farmers of America, while meat processing (a nominally-similar market) is dominated by multinational public companies.
Are there significant barriers to entry for co-ops trying to move into markets already dominated by conventional enterprises? Or vice versa, are there barriers to entry for conventional enterprises wanting to enter markets controlled by co-ops? If barriers to entry are overcome, does either form of enterprise have an ongoing competitive advantage?