Class 11 Economics (Mircoeconomics) Chapter 4 The Theory of the Firm under Perfect Competition

Key Concept: Conceptual Linkage

c) MR = Marginal Cost

[Solution Description] To maximize profit, a firm should produce up to the point where marginal revenue (MR) equals marginal cost (MC). This ensures that the revenue generated by selling an additional unit is exactly equal to the cost of producing that unit. The condition is given by:

$$MR = MC$$

Hence, for profit maximization, $$MR = MC$$.

Key Concept: Profit Maximization

c) When market price equals LRMC

[Solution Description] To maximize profit in the long run, a firm should produce at an output level where the market price equals the Long Run Marginal Cost (LRMC). This is because profit maximization occurs when marginal revenue equals marginal cost, and for perfectly competitive markets, price equals marginal revenue.

Key Concept: Demand Curve

d) Perfectly elastic

[Solution Description] In a perfectly competitive market, each firm faces a perfectly elastic demand curve because the firm can sell as much as it wants at the market price but cannot influence the price itself.

Key Concept: Real World Application, Strategic Decision Making

b) Continue production to minimize losses until the market recovers

[Solution Description]

The firm needs to decide whether to continue operations or shut down temporarily. Given that the market price is expected to rise above the firm’s minimum AVC in six months, it may be beneficial for the firm to keep operating in the short run. By continuing production, the firm can cover some of its variable costs and potentially minimize losses during this period.

– To decide effectively, the firm must consider:

1. Current AVC: If the current market price is covering AVC, the firm should continue production.

2. Expected Market Price Trends: A strong forecast of higher future prices supports sustained operation.

3. Short-term financial health and cash flow: Ensuring sufficient liquidity to maintain operations.

Overall, if the market conditions are projected to improve soon, the most strategic choice is to continue production despite short-term losses.

Key Concept: In-Depth Scenario Analysis, Advanced Reasoning

c) Firms exit, leading to increased market price and restored equilibrium

[Solution Description]

In monopolistic competition, firms earn zero economic profits in the long run, meaning price equals average total cost (P = ATC).

When input prices rise, the firm’s average cost (AC) curve shifts upwards. Assuming the firm maintains the same market price, AC increases above price, causing losses in the short run.

To return to long-run equilibrium:

1. Some firms may exit the market, reducing supply and driving up prices.

2. Alternatively, the firm might reduce output to lower costs.

The outcome is either price rises or firms exit until P = new higher AC, restoring zero economic profit.

Key Concept: Condition Identification

d) Price ≥ AVC

[Solution Description] A firm will continue to produce in the short run if the market price is greater than or equal to the Average Variable Cost (AVC). This ensures that the firm’s variable costs are covered and contributes toward fixed costs.

Key Concept: Scenario Analysis

d) Exit the market to prevent further losses.

[Solution Description] If the market price remains persistently below the firm’s minimum AVC, covering variable costs becomes impossible with any level of production. In the long run, this position is unsustainable, and the firm may opt to exit the market to avoid continuous losses that exceed its fixed costs.

Key Concept: Basic Definition

a) The MC curve remains constant or increases but never decreases.

[Solution Description] A non-decreasing MC curve means that the cost of producing an additional unit is not falling as output increases. It indicates that each additional unit is costing the same or more than the previous one, which aligns with conditions for profit maximization.

Key Concept: Price-Taking Behavior

c) It sells nothing

[Solution Description] In a perfectly competitive market, firms are price-takers. If a firm sets its price above the market price, it will sell nothing because consumers can buy the same product at a lower price from other firms.

Key Concept: Application of Formula

c) \$80

[Solution Description] To find the total revenue, we use the formula $$TR = p \times q$$, where $$p$$ is the price and $$q$$ is the quantity sold. Here, $$p = 10$$ and $$q = 8$$. Therefore:

$$TR = 10 \times 8 = 80$$

So the total revenue is \$80.

Key Concept: TR Curve and Profit Maximization, Real-World Application

d) Adjust production so that Marginal Cost equals new Marginal Revenue

[Solution Description]

With a 20\% drop in market price, the TR curve will shift downward since TR is calculated as $$TR = p \times q$$. To maximize profit, the firm needs to assess whether the new price aligns with their average cost. Since this isn’t provided, the firm’s best approach is to focus on producing where Marginal Cost (MC) equals the new Marginal Revenue (MR) derived from the decreased price. This ensures no loss is made per additional unit produced. The firm must re-evaluate output levels according to the new MR until MC and MR align.

Key Concept: Complex Scenario, Real World Application

c) Implement cost-saving technologies or raise selling prices.

[Solution Description] To maintain profitability, the firm needs to analyze the impact of the increased input prices on its cost structure. The rise in labor and raw material costs will result in a higher MC, leading to a potential decrease in output unless adjustments are made. One strategic approach could be to explore efficiency improvements or automation to mitigate rising costs. Alternatively, if the firm has sufficient market power, it may consider increasing the product’s selling price to offset the additional costs. Another option might be to differentiate its offerings to justify a higher price point without losing customers. Thus, the firm can either cut costs in other areas or pass some of the increased costs onto consumers.

Key Concept: Comparative Analysis

d) Increase output to maximize profits

[Solution Description] When the market price is above the minimum LRAC, it indicates that the firm can cover its production costs and potentially earn a profit. Therefore, the firm should produce at an output level where profits are maximized. This is typically at the point where marginal cost equals marginal revenue, assuming no constraints on capacity.

Key Concept: Real-World Application, Impact of Firm Entry/Exit

b) Shift to the left

[Solution Description]

When multiple firms exit the market, there are fewer suppliers providing goods in the market. This reduction decreases the total output available for sale at any given price, effectively shifting the market supply curve to the left.

A leftward shift indicates that less quantity is supplied at every price level compared to before the exits occurred.

Key Concept: Long Run Decision Making, Advanced Cost Analysis

d) Exit the market

[Solution Description]

Long-run decisions are based on whether the firm can sustainably cover all of its costs:

– The firm’s LRAC at minimum is \$10, which is the lowest possible cost per unit for sustainable production in the long run.

– The prevailing market price of \$9 is below the firm’s minimum LRAC, indicating that the firm cannot cover its long-run costs at the current market price.

– Consistently selling below LRAC results in losses, making continued operation unsustainable.

Thus, the firm should decide to exit the market in the long run if prices do not increase above \$10.

Key Concept: Advanced Application, Critical Thinking

b) Both Assertion and Reason are true, but Reason is NOT the correct explanation of Assertion.

[Solution Description]

When AR decreases for a firm in perfect competition, it implies that the market price has decreased. Since the firm is a price taker, AR being equal to the market price suggests this change is due to shifts in overall supply or demand. The reason correctly states that AR equals the market price; however, a decrease in AR specifically shows not just output increases but a resultant drop in price due to potentially higher supply with unchanged demand or lowered demand.

Key Concept: Complex Scenario Analysis, Long Run Adjustments

c) Equilibrium price decreases, equilibrium output increases

[Solution Description]

Technological advancements that reduce the average cost will shift the long-run supply curve downward. This typically results in a decrease in the equilibrium price due to increased competition as firms can produce at lower costs. Output levels are likely to increase because firms will be able to supply more at each price level.

– Step 1: Understand that reduced average costs allow firms to offer goods at a lower price.

– Step 2: Analyze how this impacts the industry; the supply curve shifts rightward.

– Step 3: Recognize that with supply increasing, the equilibrium price tends to decline while quantity increases.

Therefore, the equilibrium price decreases, and the output level increases.

Key Concept: Supply Schedule

a) Both Assertion and Reason are true, and Reason is the correct explanation of Assertion.

[Solution Description]

The assertion states what a supply schedule is, which is indeed a table showing quantities sold at different prices. This definition of a supply schedule is consistent with the reason provided. Additionally, for a supply schedule to accurately reflect the relationship between quantity supplied and price without the influence of other factors, it must assume constant technology and factor prices. Therefore, both the assertion and the reason are true, and the reason correctly explains why a supply schedule functions as described in the assertion.

Key Concept: Price Elasticity

c) Elastic

[Solution Description]

The price elasticity of supply ($$E_s$$) is calculated using the formula:

$$E_s = \frac{\%\ \text{change in quantity supplied}}{\%\ \text{change in price}}$$

Given that the percentage change in quantity supplied is 15\% and the percentage change in price is 10\%, we have:

$$E_s = \frac{15\%}{10\%} = 1.5$$

Since $$E_s > 1$$, the supply is elastic.

Key Concept: Long Run Tax Impact

c) The average cost curves shift upward.

[Solution Description] Imposing a unit tax increases the cost of production for each unit produced, which results in an upward shift in both the average variable cost (AVC) and average total cost (ATC) curves. This reflects the additional cost incurred per unit due to the tax.

Key Concept: Market Price Impact

c) Output becomes zero

[Solution Description] If the market price drops below the minimum Average Variable Cost (AVC), the firm would not cover its variable costs by producing any output. Hence, the most viable action for the firm is to cease production, resulting in zero output.

Key Concept: Complex Numerical Analysis, Graphical Interpretation

c) 35

[Solution Description] To find the market supply at $$p = 10$$, we first substitute $$p = 10$$ into each firm’s supply function to determine their individual supplies.

For firm 1:

\begin{align*}

S_1(10) &= 4(10) – 20

&= 40 – 20

&= 20

\end{align*}

For firm 2:

\begin{align*}

S_2(10) &= 3(10) – 15

&= 30 – 15

&= 15

\end{align*}

The total market supply is the sum of these individual supplies:

\begin{align*}

S_{\text{market}} &= S_1(10) + S_2(10)

&= 20 + 15

&= 35

\end{align*}

Thus, the total market supply at $$p = 10$$ is 35 units.

Key Concept: Marginal and Average Revenue Relationship, Profit Maximization Analysis

c) Reduce production to reduce losses

[Solution Description]

To determine the optimal production decision in a perfectly competitive market, we need to ensure that the firm’s price (\$50) equals its marginal cost (MC). Here, the MC is given as \$52 which is greater than the price (\$50), indicating that the firm is producing at a loss on additional units since each unit costs more to produce than it earns (\$52 > \$50).

For profit maximization, the firm should adjust its output until $$p = MC$$. Since increasing production increases loss (MC > p), the firm should decrease production to lower total cost and stop once MC equals or falls below price.

– Current Price (\$p\$): \$50

– Marginal Cost (MC): \$52

– Decision: Reduce output to reduce losses

Hence, reduce production.

Key Concept: Long Run Conditions, Real World Application

c) The firm’s supply curve shifts right, leading to temporary economic profits.

[Solution Description] Technological progress leads to a reduction in production costs, causing the firm’s supply curve to shift to the right. In the long run, firms make zero economic profit due to free entry and exit. However, initially, the firm may experience temporary economic profits until new firms enter the market or all firms adjust their production accordingly.

Key Concept: Elasticity and Supply, Real World Application

c) 30\%

[Solution Description] The formula for calculating the percentage change in quantity supplied using price elasticity of supply is:

$$\%\Delta Q_s = E_s \times \%\Delta P,$$

where $$E_s$$ is the price elasticity of supply, $$\%\Delta Q_s$$ is the percentage change in quantity supplied, and $$\%\Delta P$$ is the percentage change in price.

Given that $$E_s = 2$$ and $$\%\Delta P = 15\%$$, we plug these values into the formula:

$$\%\Delta Q_s = 2 \times 15\% = 30\%.$$

Therefore, the market supply increases by 30\%.

Key Concept: Simple Calculation

c) \$60

[Solution Description] To calculate the total revenue (\$TR\$), use the formula:

$$TR = p \times q$$

Here, $$p = \$15$$ and $$q = 4$$. Therefore,

\begin{align*}

TR &= 15 \times 4

&= 60

\end{align*}

Hence, the total revenue is \$60.

Key Concept: Real World Application, Strategic Decision Making

c) Maintain current output

[Solution Description]

In a perfectly competitive market, the firm’s goal is to operate where marginal cost (\$MC\$) equals price (\$P\$). Here, the condition \$P = MC\$ already holds, and since \$P > AVC\$, the firm covers variable costs and contributes towards fixed costs.

The increase in fixed costs does not affect the decision because fixed costs do not change marginal costs or the conditions for continuing production in the short run. This means, despite higher fixed costs, the firm should focus on maintaining current output as changes in fixed costs don’t impact short-run production decisions where \$P > AVC\$.

Key Concept: Revenue Calculation

c) Rs 150

[Solution Description] Total revenue ($$TR$$) is calculated using the formula $$TR = p \times q$$, where $$p$$ is the price per unit and $$q$$ is the quantity sold. Here, $$p = 15$$ and $$q = 10$$. Therefore, $$TR = 15 \times 10 = 150$$.

Key Concept: Shut Down Point Analysis

b) SMC cuts AVC at its minimum

[Solution Description] The shut down point in the short run occurs at the minimum point of the Average Variable Cost (AVC) curve where it intersects with the Short Run Marginal Cost (SMC) curve. This implies that at this point, the SMC is equal to the AVC.

Key Concept: Basic Concept

b) Setting marginal cost equal to marginal revenue: \$MC = MR\$

[Solution Description] For a firm to maximise profit in a perfectly competitive market, it must set its output level where marginal revenue ($$MR$$) equals marginal cost ($$MC$$). Since $$MR = P$$, the condition simplifies to $$P = MC$$.

Key Concept: Elasticity and Input Prices, Real World Application

b) Decreases

[Solution Description] When input prices increase and craftsmen are unable to pass the full cost on to consumers, they may become less responsive to price changes due to higher production costs relative to selling prices. This results in a decrease in the price elasticity of supply as it becomes harder for them to alter production levels significantly when prices change.

Key Concept: Long Run Supply Curve

a) Both Assertion and Reason are true, and Reason is the correct explanation of Assertion.

[Solution Description] The assertion states that the long-run supply curve for a firm corresponds to the part of the long-run marginal cost (LRMC) curve that lies above the minimum of the long-run average cost (LRAC). This is because, in the long run, only at prices where the LRMC is greater than or equal to the LRAC will the firm be willing and able to supply. On the other hand, the reason correctly explains why this condition exists; in the long run, firms need to ensure they can cover their total costs, which include both fixed and variable components. Thus, both the assertion and the reason are true, and the reason accurately explains the assertion.

Key Concept: Long Run Exit Decision, AVC and AC Comparison

d) Exit the market due to unsustainable losses

[Solution Description] If the average cost (AC) is greater than the market price over the long term, it implies the firm is incurring losses. For sustainability, firms need at least zero economic profit ($$TR = TC$$), meaning the situation will compel the firm to exit the market to stop losses.

Key Concept: Strategic Decision Making, Real-world Applications

a) Plan A

[Solution Description] Calculate break-even points for each plan.

For Plan A:

$$12x = 10000 + 5x$$

Solve for $$x$$:

\begin{align*}

12x – 5x &= 10000

7x &= 10000

x &= \frac{10000}{7} \approx 1428.57

\end{align*}

For Plan B:

$$12x = 15000 + 3x$$

Solve for $$x$$:

\begin{align*}

12x – 3x &= 15000

9x &= 15000

x &= \frac{15000}{9} \approx 1666.67

\end{align*}

Plan A has a lower break-even point at approximately 1429 units compared to Plan B’s 1667 units.

Key Concept: Supply Curve Derivation

c) It is the rising part of the SMC curve from and above the minimum AVC.

[Solution Description] The short run supply curve is identified by the segment of the SMC curve that lies above the minimum AVC. This means that the firm will supply a positive quantity of goods as long as the market price is above the minimum AVC. Thus, the rising part of the SMC curve starting from the point where it intersects the AVC curve at its minimum is the short run supply curve.

Key Concept: Basic Definition

c) Total Revenue and Total Cost

[Solution Description]

Profit ($$\pi$$) is calculated as the difference between total revenue (TR) and total cost (TC). Mathematically, this is represented by the equation $$\pi = TR – TC$$.

Key Concept: Elasticity and Taxation, Elasticity and Market Dynamics

c) Both increased input costs and the tax contributed to reducing elasticity.

[Solution Description]

Initially, we have $$e_S = 1.5$$. After a 10\% increase in input prices and a subsequent 5\% increase in product prices due to a specific tax, the elasticity drops to $$e_S = 1.2$$. This scenario can be understood as follows:

– An initial elasticity greater than one indicates that the firm’s output is quite responsive to price changes.

– The increase in input prices reduces the firm’s ability to expand production when prices rise since costs are higher.

– Imposing a specific tax typically shifts the supply curve upwards, reducing responsiveness further.

Therefore, the decrease in elasticity suggests that the combination of increased input costs and taxes has reduced the flexibility of quantity supplied relative to price changes.

Thus, the most plausible explanation is that the combined effect of increased input costs and taxation decreased the elasticity from 1.5 to 1.2.

Key Concept: Shut Down vs Break-even

b) Firm breaks even, covering all its costs

[Solution Description] When the market price is exactly equal to the minimum LRAC, the firm covers all its costs including normal profit but earns no supernormal profit. This condition represents the break-even point. Since the firm covers all costs, it continues production without loss or shutdown.

Key Concept: Economic Implications, Comparative Advantage

c) Enhanced overall productivity and consumer welfare

[Solution Description]

When numerous firms within an industry benefit from technological progress leading to reduced production costs, it can enhance overall market efficiency and consumer welfare through lower prices. Additionally, widespread adoption can drive down industry-wide average costs, leading to more aggressive pricing competition, benefitting consumers. Concurrently, firms that do not adopt such innovations might struggle to compete, possibly forcing them out of the market, thereby reshaping the industry’s competitive landscape and potentially reducing the number of market players in the short term.

Key Concept: Basic Concept

d) Price is greater than or equal to average cost (AC)

[Solution Description] For a firm to continue production in the long run, the price ($$p$$) must be greater than or equal to the average cost (AC). This ensures that the firm covers all its costs and earns normal profit.

Key Concept: Real World Application, Advanced Profit Analysis

b) Invest in enhancing product quality or technology

[Solution Description] As new entrants are attracted by super-normal profits, the firm needs to prepare for a more competitive environment where only normal profits can be sustained. The firm should focus on improving efficiencies or product differentiation to maintain a competitive edge when prices converge to LRMC = LRAC.

Key Concept: Basic Definition

a) $$MR = MC$$ and $$p \geq AVC$$

[Solution Description] In the short run, a firm maximizes its profit when marginal revenue (MR) equals marginal cost (MC). Additionally, to continue production, the market price ($$p$$) must be greater than or equal to average variable cost (AVC).

Key Concept: Graphical Analysis, Strategic Decision Making

b) Exit the market

[Solution Description]

When LRMC intersects AR below the minimum ATC, the firm is not covering all its costs, including normal profit, implying less than normal profit or losses. Under these circumstances, in the long run, the firm should consider exiting the market because continued operation will not cover all necessary costs.

Since making less than normal profits isn’t sustainable long term due to incurring losses, especially when fixed costs can’t be covered, the logical strategic step is to exit the market.