This is a story about the difference between working from home in theory and working from home in practice–and a key rule that everyone is now ignoring.

But to put it in context, we need to acknowledge two big things.

First, while employees have been asking for more flexibility for years, there’s been a lack of good research on remote work productivity.

That’s because, historically, it’s been hard to find groups of workers who do the exact same jobs–but where a significant number work from home, and a significant number work in an office.