Typically the publisher retains copyright, they make the author(s) sign it away as a condition of publication. There are some exceptions. By inserting themsel

Typically the publisher retains copyright, they make the author(s) sign it away as a condition of publication. There are some exceptions. By inserting themselves into the somewhat "broken" system of scientific publishing, the large publishers have been making a killing. (It's broken from an economic point of view because too much work is done for free.)