Yes, growth is slow. Yes, the ultimate source of growth is productivity. But no, sclerotic productivity is not "just being ordinary." No, our economy is not generating as much productivity growth as is possible, so just get used to it. No, productivity does not fall randomly from the sky no matter what politicians do.
Mark starts well, with a nice and vivid review of the post WWII growth "miracles."
He stumbles a bit at the 1973 Yom Kippur war and oil embargo
"Politicians everywhere responded by putting energy high on their agendas. In the U.S., the crusade for “energy independence” led to energy efficiency standards, the creation of the Strategic Petroleum Reserve, large government investments in solar power and nuclear fusion, and price deregulation. [JC: ?? The 1970s had price controls, not deregulation!] But it wasn’t the price of gasoline that brought the long run of global prosperity to an end. It just diverted attention from a more fundamental problem: Productivity growth had slowed sharply."
"The consequences of the productivity bust were severe.."More good descriptions of eurosclerosis follow. But you see him veer off course, as he sees little connection between the litany of ham-handed responses to the oil shock and the decline in productivity.