I’ve got to think about that one, it definitely seems worthy of consideration, thanks for adding. I have noticed in my life that my expenditure does grow to meet my income, and earning more money (getting a new job or a big raise or a bonus) never feels like that much more because it’s so easy to use up the extra. My life seems to expand and contract to match whatever money I’ve got. In that sense, the comment you read feels true.

On the other hand, it’s typically employers that generally control hours and pay, and employers that both seek and use most of the profits from productivity; employees often only get the scraps. If employers are the major force for asking people to work hard, and offering jobs and pay, how does that fit into the idea of debt eating the productivity gains? Are we talking about corporate debt here?

I think a reasonably simple example would be the relationship between private debt and the property market.

Increased productivity -> increased income -> increased discretionary income -> increased ability to service debt -> larger mortgages -> higher property prices -> less discretionary income (which could otherwise have been used to 'buy' free time).

It's true that some of this borrowing will lead to new wealth in the form of new houses and associated infrastructure, but I suspect that a large amount - if not most - of the borrowed money is spent on driving up the prices of existing assets, in which case the winners are the lenders who have successfully captured the increase in productivity.