Well, they certainly are, you need a much smaller department to do the same things, and those departments relied on people like "secretarial pool" for typing do

Well, they certainly are, you need a much smaller department to do the same things, and those departments relied on people like "secretarial pool" for typing documents, people carrying internal mail, etc - so productivity of generic business administration tasks certainly has increased. However all of those gains would appear with basic "office computerization" in late 1990s and early 2000s (which is quite visible as productivity growth in the article) with wordperfect/word and visicalc/1-2-3/excel, and not meaningfully changed with more recent develpoments. Accounting today is automated roughly as much as you could in 2000, at least if you were up to date with year 2000 tech.