He writes,

Has productivity growth in consumption really been flat since the early 1970s? No meaningful gains at all? This does not pass the smell test, yet this is one of the best TFP measures. This suggest there are big measurement problems in consumption production. And I suspect they can be traced to the service sector. I suspect if these measurement problems were fixed there would be less support for secular stagnation (and maybe for the Great Stagnation view too).

Actually, he wrote that some time ago, and he then quoted himself.

Put it this way. We do not have reliable measures of real GDP. Tell me how to measure output in health care, education, financial services, etc.

We do not have reliable measures of labor input. Tell me how to measure human capital. Tell me how to distinguish labor used in production from labor used to build organizational capital.

Labor productivity is the ratio of these two unmeasurables. Labor productivity growth is the percent change in those two unmeasurables. Economist John Fernald runs statistical algorithms on the moving average of this percent change in order to arrive at “breaks” in productivity trends. He makes the point (like Beckworth, I attended this conference) that measurement error ought to behave smoothly, so that the broken trends that he fits to the data should be indicating real change. But at that same conference, Steve Oliner showed that a measure of productivity in the computer industry shows a decline because the government statisticians were using an approach to tracking prices that may have been accurate in 2001 but greatly under-estimated price declines (and hence under-estimated productivity) by the end of that decade. Steve argued for humility in any claim to measure or forecast productivity trends, and I think that is an important take-away from the conference.