dave submitted another article which related to work productivity. From the last paragraph:

It turns out that the afternoon games have a real economic impact. A new study shows that all the afternoon playoff games cost employers $225 million in lost productivity. The outplacement firm that came up with the figure said that the biggest impact will obviously be on companies in the eight cities that have teams in the playoffs.

I'm assuming that this study assumed that the time would have otherwise been productive, which may be questionable :)