Morning Scepticism: Productive

Every time I hear about how X many millions of dollars is being wasted away at work through workers engaging in non-work activities I've got to wonder just how they calculate it. It seems there's the blunt figure of time lost equals dollars lost, which I wonder how much quality of work factors in. I know from my line of work keeping people overtime doesn't necessarily mean they get more done. So when figures quoting Facebook are put in the economy's deficit, I've got to wonder if someone using Facebook for an hour makes them happier and that helps productivity then the quoted figures are naive speculation.