The law of increasing marginal cost does not fit the reality.

- [law of increasing marginal cost](/en/law%20of%20increasing%20marginal%20cost) : When you make a lot, the production cost goes up.
- This is the opposite of [economies of scale
- Even as a practical matter, [marginal cost](/en/marginal%20cost) goes down with mass production.
- So I looked it up and found some discussion about it.
- The upward-sloping [supply curve](/en/supply%20curve) focuses only on the mass-production part of the U-shaped [average cost curve](/en/average%20cost%20curve) shown below.
    - ![image](https://gyazo.com/7dd35c64ac7e9b7d61c6354bfd1edd1e/thumb/1000)
        - The average cost curve is the slope of the line connecting each point of the total cost curve to the origin.

- As for new manufacturing from 0 to 1, the supply curve is falling right
- ![image](https://gyazo.com/8541f44cfa945c9b9b80589f577b4cd9/thumb/1000)
- If the supply curve exceeds the demand curve, the supplier "is in the red" and the demander "is too expensive".
- If this is reversed, the supplier "is in the black" and the demander "wants it!" and the demander says, "I want it!

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