If there is no difference in value between the money and the food, then why did you exchange the money for the food? Why not just keep your money and skip the trip to the store?

Same with the store: why bother selling the food for money? If the value is the same, why doesn’t the store just keep the food and save themselves the trouble?

The alchemical transformation between needs is in fact what money is for. And money is lost in the transformation due to friction. The computer age is impressive but easily overlooks advances in fields, like Foucault's Order of Things and his presentation of Economic theory. Such awareness would prevent such drastic oversimplifications imo

The store buys low and sells high, that’s the value. The end consumer does not... unless they are baking a cake to sell or something.

From another angle, why would the customer spend their time (which has value to them) in a transaction where they don't get any?

> From another angle, why would the customer spend their time (which has value to them) in a transaction where they don't get any?

Well I for one always took issue with the rational consumer model. It is possible that people trade things they value for things they don't, because people do not always act rationally.

That’s a larger discussion but much of the economics of it gets cancelled out with the notion of “revealed preferences”. Economics doesn’t really account for whether an individual consumer is rational for buying junk food, scratch tickets, and liquor; it just sort of observes that you behave as though you want those things and models from there. The internal struggle of will between the “you” who binges on Oreos and store brand vodka and the “you” who wakes up on New Years morning with a hangover and a sincere desire to turn your life around isn’t necessarily within the scope of economics (unless the New Years Day “you” promptly purchases a gym membership that you never show up for!)

But we're talking about basic stuff here like buying bread...

Have you seen the variety of bread available, and the price range thereof? If all of it is purchased on rational valuation grounds, I think we must end up with a fairly loose definition of "value"

I'm sorry, but you still seem to be missing the point ? This isn't about bread varieties either, I would assume that most bread is bought within an order of magnitude of prices.

What's the difference between buying flour etc. to bake a cake to sell, and buying food to eat, so I can continue to function and sell my labour?

This is incorrect. You agree to trade because you value the food (and eating the food) more than the money. The store agrees to trade because they value the money more than the food. Each side is more satisfied after the trade than before. Hence it's non-zero sum.

If they don't buy it from the store, they have to make it themselves. Everybody are satisfied in the transaction because they played well on this trivial zero sum game instead of falling into a negative sum swirl.

By the way, economic concepts are statistics. Arguments are only meaningful on large number of samples or over long period of time.

It’s not... see https://www.google.com/amp/s/www.thestreet.com/.amp/politics...

You'll only pay $X for a good if it's worth at least $X to you, so in the absence of perfect price discrimination, that trade is also positive-sum: https://en.wikipedia.org/wiki/Economic_surplus#Consumer_surp...

In other words, if a banana costs $1 and I buy it, its value to me is at least $1

That’s an illusion if you can’t use it directly to make more money. In the abstract sure it’s positive value but for this simulation or any simulation it doesn’t matter.

The transaction has impacts beyond the immediate direct interaction, and those must also be considered. Examples:

* The company now has more money for research and development, which will result in the creation of new value.

* Demand has been demonstrably increased (from the moment before the transaction), providing a small but real signal that production should increase. Increased production will result in new value being created.

And so on. This is all on average, of course. Some companies destroy value through incompetence, ignorance, malicious action, or other mechanisms.