> bottom line: several key technological leaps can't really ever happen again - ... - these made huge fundamental changes in living standards - no comparably huge changes remain

I have some ideas for "huge fundamental changes in living standards": cheap (as in almost free) housing, not having to work 40 hours a week. Why are these not on a list of technological possibilities?

Given that we don't know what advances lie in the future, I just don't understand how one can say "no comparably huge changes remain", as this is equivalent to a prediction about the future, and those are notoriously terrible.

Future predictors always want you to ignore the hundreds of times they've previously been wrong, and just get you to focus on this one call here.

brain augmentation, space travel and life extension would reshape humanity just as much, if not more than indoor plumbing, telecom and air travel.

No to mention that we actually lack the ability to grow abundant food without destructive environmental effects. Lots of research and business capital is going into new ways to grow food in smaller spaces. There is even development of meat that can be grown. These would fundamentally change society.

Krugman was also a very lonely voice going against conventional wisdom and time has proven him right on some big bets.

Contrarian Call #1 - He called bullshit on the rationale for the Iraq war very early.

Contrarian Call #2 - His models showed that the stimulus and bailouts after the financial collapse would not cause runaway inflation.

If you read his review of the book (not an endorsement) you'll see that it's Contrarian Call #3 -- that maybe the bulk of productivity improvements from the internet have already been achieved.

Let's discuss the ideas, evidence and models, not take ad hominem shortcuts.

To clarify your criticism, the definition of ad hominiem (from Wikipedia) is: "argumentum ad hominem, is a logical fallacy in which an argument is rebutted by attacking the character, motive, or other attribute of the person making the argument...".

I criticized him as having a bad history of predicting things (not his personality, position, or viewpoint), and history is the best predictor of future performance. Krugman said that the internet was similar to the fax (back in the 1990s), and was wrong; however, I will grant that Krugman may not be as bad as other NYT columnists.

Krugman, circa 1995: "By 2005 or so, it will become clear that the Internet's impact on the economy has been no greater than the fax machine's."