Question

Do you think it is rational for a producer to strike equilibrium when $MC$ is rising, not when it is falling?

Answer 1

Yes, it is rational for a producer to strike equilibrium when $MC$ is rising, not when it is falling. When $MC$ is falling, cost of producing an additional units tends to fall. Other things remaining constant, it would lead to a rise in total profits. A producer would not stop production when the total profits are rising, it would not be a rational decision. The equilibrium will, therefore, be struck only when $MC$ is rising, and is equal to $MR$.