Which of the following conditions must hold for a firm to maximise its profit.

(A) Price= Short run marginal Cost

(B) Short Run marginal cost curve is non-decreasing

(C) Price ≤ Marginal Cost (D) Price ≥ Average variable cost

Choose the correct answer from the options given below:

The correct answer is (A), (B) and (D) only.

For a profit-maximizing firm operating in a perfectly competitive market, three distinct conditions must be satisfied to ensure that the chosen output level maximizes profit in the short run:

1. Condition (A): Price = Short-run Marginal Cost (P = SMC)
A firm maximizes profit where marginal revenue (MR) equals marginal cost (MC). In a perfectly competitive market, the price (P) is determined by the market, meaning the firm's marginal revenue is equal to the price (P = MR). Therefore, the profit-maximizing condition simplifies to Price = Short-run Marginal Cost (P = SMC). If price were greater than marginal cost, the firm could increase profit by producing more. If price were less than marginal cost, the firm could increase profit by producing less.

2. Condition (B): Short-run marginal cost curve is non-decreasing
This is the second-order condition for profit maximization. It ensures that the marginal cost curve cuts the marginal revenue (price) curve from below at the profit-maximizing output level. If the marginal cost curve were decreasing, producing an additional unit would cost less than the previous one, meaning the firm could continue to increase its profit by expanding output. Thus, for profit to be maximized, the SMC curve must be upward-sloping (non-decreasing) at the point of equilibrium.

3. Condition (D): Price ≥ Average variable cost (P ≥ AVC)
In the short run, a firm has fixed costs that it must pay even if it produces zero output. Therefore, the firm will continue to operate as long as its total revenue covers at least its total variable costs. On a per-unit basis, this means the price must be greater than or equal to the average variable cost (P ≥ AVC). If the price falls below the AVC, the firm will minimize its losses by shutting down immediately because it cannot even cover its operating costs.

Why Condition (C) is incorrect:
Condition (C) states that Price ≤ Marginal Cost. This is not a condition for profit maximization. Profit maximization strictly requires Price = Marginal Cost (Condition A) rather than Price being less than or equal to Marginal Cost.