CBSE Class 12 Economics: Producer Equilibrium NCERT Solutions

For a profit-maximizing firm to produce a positive output in a competitive market where the price is constant, two fundamental conditions must be met, as explained by the Marginal Revenue (MR) and Marginal Cost (MC) approach:

1. MR = MC: The firm will produce up to the point where its Marginal Revenue equals its Marginal Cost. If MR is greater than MC, the firm can increase its profits by producing more units, as each additional unit brings in more revenue than it costs to produce. If MR is less than MC, the firm is losing money on the last units produced and can increase profits by reducing output.
2. MC must be rising: At the point where MR = MC, the Marginal Cost curve must be upward sloping. This means that the MC curve is cutting the MR curve from below. This condition ensures that the firm is at a point of maximum profit. If MC were falling at the point where MR = MC, producing more units would lead to lower profits or even losses, indicating that this is not the profit-maximizing output level.

Implications of the Conditions:

• When MR > MC, the firm finds it profitable to increase production because each additional unit adds more to revenue than to cost.
• When MR < MC, the firm finds it unprofitable to produce the last unit(s) and will reduce output to increase profits.
• The equilibrium is achieved only when both conditions (MR = MC and rising MC) are satisfied, leading to the highest possible profit for the firm.

Example using a Table:

Consider the following data:

In this table, MR is constant at ₹8. The conditions for producer equilibrium are met at 4 units of output:

• At 4 units, MR = MC (₹8 = ₹8).
• At 4 units, MC is rising (MC was ₹7 at 3 units, ₹8 at 4 units, and ₹9 at 5 units).

Although MR = MC at 2 units, the MC is falling (from ₹8 at 2 units to ₹7 at 3 units), so this is not the equilibrium point. Producing beyond 4 units (e.g., 5 units) results in MC > MR (₹9 > ₹8), reducing profits.

Diagrammatic Explanation:

In a diagram where output is on the horizontal axis and cost/revenue on the vertical axis, the producer's equilibrium is determined at point E, where the MC curve intersects the MR curve from below. At this point (OQ level of output), MC = MR, and the MC curve is upward sloping.

The firm will continue to produce as long as MR > MC (up to point E) and will reduce output if MR < MC (beyond point E).

No, there cannot be a positive level of output at which a profit-maximizing firm produces in a competitive market where the market price is not equal to the marginal cost. For a firm to be in profit-maximizing equilibrium in a competitive market, two conditions must hold: MR = MC, and MC must be rising. In a perfectly competitive market, the market price (P) is constant and equal to Marginal Revenue (MR). Therefore, the condition MR = MC becomes P = MC.

If the market price is not equal to MC, the firm is not at its profit-maximizing output level. This can be explained by considering two cases:

Case 1: Market Price (P) > Marginal Cost (MC)

Suppose a firm is producing at an output level (say, $q\_2$) where the market price is greater than the marginal cost ($P\; >\; MC$). This implies that MR > MC. In this situation, the firm can increase its total profit by increasing its output. The additional revenue gained from selling one more unit (equal to the market price) is greater than the additional cost incurred to produce that unit (MC). The firm will continue to increase its output until the point where the market price equals the marginal cost ($P\; =\; MC$), as this is where profits are maximized.

Consider an output level $q\_3$ greater than $q\_2$. The increase in total revenue from producing from $q\_2$ to $q\_3$ is the area of the rectangle $q\_2q\_3CB$ (which equals $P\; \backslash times\; (q\_3\; -\; q\_2)$). The increase in total cost for the same output range is the area under the MC curve from $q\_2$ to $q\_3$ (area $q\_2q\_3XW$). Since $P\; >\; MC$ over this range, the additional revenue is greater than the additional cost, leading to higher profits at $q\_3$ than at $q\_2$.

Case 2: Market Price (P) < Marginal Cost (MC)

Suppose a firm is producing at an output level (say, $q\_2$) where the market price is less than the marginal cost (). This implies that MR < MC. In this situation, the firm is incurring a loss on the last units produced because the cost of producing them exceeds the revenue they generate. To maximize profits (or minimize losses), the firm should reduce its output. It will continue to reduce output until the point where the market price equals the marginal cost ($P\; =\; MC$).

Consider an output level $q\_3$ less than $q\_2$. By reducing output from $q\_2$ to $q\_3$, the firm saves on costs (area under MC curve from $q\_3$ to $q\_2$) that are greater than the revenue lost (area of rectangle $q\_3q\_2AB$). This reduction in output leads to higher profits (or smaller losses) compared to producing at $q\_2$.

Therefore, for a profit-maximizing firm in a competitive market, the market price must always be equal to the marginal cost at the equilibrium level of output, provided the MC curve is rising.