My guess is it's related to inflation. Changing costs can cause people and companies to adjust to different economic conditions, and that adjustment can hurt pr

My guess is it's related to inflation. Changing costs can cause people and companies to adjust to different economic conditions, and that adjustment can hurt productivity. Something similar happened in the mid-seventies. https://fred.stlouisfed.org/series/OPHNFB https://fred.stlouisfed.org/series/OPHNFB