As a critical approach to analysing contemporary media systems, political economy identifies problems caused by market structures that governments, in turn, seek to ameliorate via cultural policy interventions. The political economy approach is the oldest of the theoretical movements that gave rise to the modern academic discipline of media studies. As such, political economy traces its intellectual lineage not from history, literary studies or bibliography but from the combination of left-wing social theory, economics and aesthetic philosophy undertaken by the so-called Frankfurt School. The contemporary publishing world is best understood as an ecosystem, incorporating many stakeholders whose interests are frequently complementary, although they may also pull in opposite directions. Commissioning editors in such firms frequently have passionately held views on literary worth, and champion these, but titles are signed up only after approval by an acquisitions committee for which sales forecasts will be a determining factor.