He also wrote an entire book on the subject, and gave numerous talks on the subject. It's very easy to hear the main parts of his argument without grasping with

He also wrote an entire book on the subject, and gave numerous talks on the subject. It's very easy to hear the main parts of his argument without grasping with spreadsheets. His point was that, if you take the trouble to disagree with him (you being another academic, a reporter, etc), then you should also actually grapple with the numbers. Which I think is valid.