The timers at grocery checkout does not 'aid' productivity. It sure does cause people to work harder. There are a lot of these computer based taskmasters out there for a huge range of jobs. Scheduling assistants very closely match number of workers with expected and observed demand. So, now every hour can be rush hour.

etc etc.

Either : "The timers at grocery checkout does not 'aid' productivity."

Or: "It sure does cause people to work harder."

Both of these sentences cannot be true at the same time.

/drove a checkout part time for 4 years a while back, proud of my scan rates. There is an art to it the mastery of which brings great satisfaction.

They mean different things. Productivity 'Aid' generally reduces effort required, such as google search or a nail gun. Playing music is a classic motivator that does not reduce effort.

PS: I am sure the company’s bottom line loved your metrics. But, again that’s just driving corporate profits not middle class incomes.