As reasons for defenestration go, missing out on $28bn is pretty emphatic. Such is the difference between the value of Microsoft’s January approach to Yahoo and its market capitalisation on Monday before news of Jerry Yang’s resignation as chief executive broke. No doubt he will be dismayed by yesterday’s one-tenth jump in the share price of the company he co-founded. Hewlett-Packard managed a similar leap yesterday following strong fourth quarter results. Yet the writing was on the wall at Yahoo the moment a search deal  with Google collapsed this month.

Blame should be spread more broadly. Mr Yang had the support of the board, even after the activist investor Carl Icahn joined in the summer. Roy Bostock, Yahoo chairman, was at least as culpable in the failure of negotiations with Microsoft. Meanwhile, the seeds of Yahoo’s predicament – that it allowed Google to build an unassailable lead in search – were planted well ahead of Mr Yang’s latest 17-month tenure.