Being able to build something, or at least having some knowledge about how something is built is sort of beautiful. It’s a kind of hidden superpower. Whenever I see a new apartment building or street being built, it always crosses my mind how the people in this line of work are paid less, on average, than those in offices. It appears that the work of those building the houses and streets is more valuable than those of the management class, so why are they paid less?
To answer this question, you need to stop thinking “in totality”, and rather “on the margin”. The total importance of a good or service does not determine its price. Its scarcity at the margin does. Keyne’s describes this in the Diamond-Water Paradox: The total value of water is much greater than that of diamonds but since water is abundant, the marginal value of water is much less than that of diamonds, and thus the reason for the low price.
We would say that the marginal revenue of product (MRP) of the construction worker is low relative to the finance worker. The construction worker’s marginal output is limited by their physical capability (e.g., how many bricks can be laid). Yes, machines may increase output, albeit, we are still bottlenecked by physics. On the other hand, the finance worker is much more leveraged. The trader may have access to a large trading account which can result in significant profits for the company relating to a much higher MRP. Moreover, the construction field is considered to have an elastic supply curve, i.e., the amount of available workers is much higher than that of finance because barriers to entry are lower and skills can be learned in a shorter amount of time.
So yeah, think on the margin.