From nymag:

The academics presented findings showing that in Wisconsin, Clinton received 7 percent fewer votes in counties that relied on electronic-voting machines compared with counties that used optical scanners and paper ballots. Based on this statistical analysis, Clinton may have been denied as many as 30,000 votes; she lost Wisconsin by 27,000.

But Alex’s omission of these numbers in this post is curious. The 7% doesn’t appear to control for other features like race and education, which Nate Silver did and found the effect disappears.

Still, the totals are close enough that a recount seems like a good idea.