His page at http://people.ischool.berkeley.edu/~hal/ says he's retired from Cal and now at Google.

I've bookmarked his page of academic papers. Unsurprisingly, since his getting affiliated with Google about 8 years ago, he's written on economics of Search: http://people.ischool.berkeley.edu/~hal/people/hal/papers.ht... and on the Google Library Project.

Sure wish he (or someone) would be funded to do an update of this (2000 pub date) study. I wonder what additional variables might need to be factored in by now.