The consequences of publishers' decisions to shift costs onto academics and their institutions can be seen in their financial results. See e.g., the results for the academic publishing division of Informa (owners of Taylor and Francis, among others): https://informa.com/investors/financial-summary/
For 2017, these show an adjusted operating profit of £208million on revenue of £530m, or an operating margin (i.e., profit) of an astonishing 39.2%. Not every academic publisher is this profitable, but then not every academic publisher charges the fees that Routledge and others in the Informa group do.

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