Does anyone know how productivity for knowledge workers is actually measured? The article only goes so far as to mention that measuring productivity is "particularly tricky", but what datapoints exactly are these statistics even pulling from?
In aggregate you measure it based on how much the company spends vs how much it makes off sold product. It's a measure of the efficiency of the company to its holders of capital.
But there are a bunch of ways to measure it, that generally comes down to some comparison of inputs vs outputs and those inputs and outputs have to be measurable in some way in aggregate.
If you Google for "economic productivity" or "labor productivity" you can find better explanations of the details than I'm likely to give.