I've been a subscriber for a long time, and thought it worth filing a support request. After a few months of alternating silence and "we've forwarded your request to the relevant team", I received a more encouraging reply:

6th July: "We have confirmed that this is an issue affecting Linux users. We're currently working on the fix and hope to have this resolved as soon as possible."

Today, 12th July, I received another response: "We have checked the records and can confirm that the browser through which you are trying to access is not supported by Economist.com.

Please find the information about supported browsers can be located at www.economist.com/help/techspecs"

A disappointing response.