It was a rare marketing opportunity. In honor of Pac-Man's 30th anniversary, Google transformed its homepage into a mini Pac-Man video game. Across the world, white collar stiffs were spending hours online playing the arcade throwback. Enter RescueTime, a company that sells employee-monitoring software.

RescueTime claimed to have figured out the estimated productivity cost of employees playing Pac-Man on the job. The number was staggering. "Google Pac-Man consumed 4,819,352 hours of time," wrote the RescueTime company blog. A time drain they say left a $120 million hole in the economy. In no time, hundreds of blogs and websites linked to the post sending the company a torrent of traffic and publicity. The statistic spread like wildfire. "A productivity blog figured out that we wasted... over 4.8 million hours of time on Friday," reported CNN.

But a few days after the media flurry, a pair of diligent thinkers have raised doubts about RescueTime's findings. The first is Howard Steven Friedman, a United Nations statistician and health economist. He doesn't split hairs:
Probably the biggest reason why this argument is incorrect is the assumption of substitution. This analysis assumes that the time the worker spent playing Pac-Man substituted for productive work. It ignores the fact that workers don't spend all of their hours at the office at work and so a certain percent of time everyday is spent on non-work activities whether that be lunch, talking around the water cooler, playing with their new I-pad, chatting with friends or any other of the countless activities available while we are at the office. The Pac-Mac entertainment could easily have substituted for other non-work activities which, of course, were not measured. Imagine someone has just spent 10 minutes gobbling ghosts and then realizes that they still have to do their work, they will either spend less time that work day on other non-work activities (water cooler, I-pad...) or they will often stay later.
Then there's Mitch Wagner, a technology enthusiast who writes for Computer World. His arguments have more to do with RescueTime's assumptions about worker productivity.
The study fails to take into account the value of rest and play -- just as an athlete performs better if he takes time out occasionally to relax and rehydrate, a knowledge worker performs better if she takes the occasional break during the day, and plays Pac-Man or looks at LOLcats or does something else to let the brain cool down.
Also worth mentioning is Friedman's second criticism about the likelihood that workers would simply put in extra hours:
The author's false argument about substitution also extends to the fact that the calculation ignores that many workers will end up spending a little more time at work in order to finish what they needed to accomplish that day. Project work is less dependent on hours and more depending on achieving milestones. Workers who are able to avail themselves to Pac-Mac games in the middle of the day may often be on project work and thus find themselves having to stay a little later to complete the work.
To see the company's complete findings see here. Mathematical quibbling is always encouraged in our comments section.