Great article. I’ve always been fascinated by the question “where does the value of things really come from?” And this article touches on that. Everything ultimately goes back to the fundamental ways we create wealth, and how much time and energy we expend doing it. The article mentions No.3 as containing most services which involve transforming goods. I wonder where do personal services like massage, and prostitution come into that?

Or what about friendship or a romantic partner? A husband or wife cannot be converted into money but I’d say having one is to most people a definite kind of wealth.

You might call these ‘emotional services’, and group them in with art and entertainment in general. I would say this is at least different enough from manufacturing to warrant their own category. Edit: rewording