Christopher Tkaczyk, CNN Money:

Mayer defended her decision by first acknowledging that “people are more productive when they’re alone,” and then stressed “but they’re more collaborative and innovative when they’re together. Some of the best ideas come from pulling two different ideas together.” The shift in policy affects roughly 200 of Yahoo’s 12,000 employees.

People can collaborate and innovate without working in the same office, as well. It’s all a matter of effective personnel management and effective use of appropriate technology.