"Still true: 'a discussion with the likes of Brad DeLong is not productive' "

A couple of years ago, Stephen Bainbridge wrote a post entitled "a discussion with the likes of Brad DeLong is not productive".  Now William Jacobson has this post entitled: "Still true: 'a discussion with the likes of Brad DeLong is not productive'”

The class clown of the academic internet is beclowning again; must be he’s upset with my investigation into Elizabeth Warren so he attacks the only way he knows how. Rather than address the merits, he picks a three and one-half year old post of mine and calls me names. Class act. . . .

I know Brad's Dad and sister, and both are extremely nice people.  It is not at all clear what could have turned him into the type of person he is today.