Microeconomics Quiz: Perfect Competition
20 questions · exam conditions
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Perfect CompetitionQuestion 1 of 20

The industry for artisanal cheese is perfectly competitive. As new firms enter the industry, they increase the demand for a rare type of milk, which is produced by a limited number of specialized farms. This increased demand for the rare milk causes its price to rise for all cheese-making firms. What does this imply about the long-run industry supply curve for artisanal cheese?

It is upward-sloping.
It is perfectly elastic.
It is downward-sloping.
It is perfectly inelastic.
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Microeconomics Quiz

Microeconomics Quiz: Perfect Competition

Practice Perfect Competition in Microeconomics with focused quiz questions that help you check what you know, review explanations, and build confidence with test-style prompts.

What this quiz covers

This quiz focuses on Perfect Competition, giving you a quick way to practice the rules, question types, and explanations that matter most for Microeconomics.

How to use this quiz

Try each quiz question before looking at the correct answer. Use the explanations to review missed ideas, then come back to similar questions until the pattern feels familiar.

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Question 1

The industry for artisanal cheese is perfectly competitive. As new firms enter the industry, they increase the demand for a rare type of milk, which is produced by a limited number of specialized farms. This increased demand for the rare milk causes its price to rise for all cheese-making firms. What does this imply about the long-run industry supply curve for artisanal cheese?

  1. It is upward-sloping. (correct answer)
  2. It is perfectly elastic.
  3. It is downward-sloping.
  4. It is perfectly inelastic.
Explanation: This scenario describes an increasing-cost industry. When new firms enter, the increased demand for a key, limited input (rare milk) drives up the price of that input. This raises the average total costs for all firms in the industry. As a result, a higher market price is required to bring forth a greater long-run industry output and maintain zero economic profit. An industry where the long-run equilibrium price increases as industry output expands has an upward-sloping long-run supply curve.

Question 2

A perfectly competitive firm has the following cost structure: fixed costs of $100, and variable costs given by $VC=q2+4qVC = q^2 + 4q $. If the market price is $16, what is the firm's producer surplus at the profit-maximizing output level?

  1. $24
  2. $36 (correct answer)
  3. $48
  4. $64
Explanation: First, find MC by taking the derivative of VC: MC = 2q + 4. At profit maximization, P = MC, so 16 = 2q + 4, giving q = 6. Producer surplus equals the area above the MC curve and below price, from q = 0 to q = 6. This is the integral: ∫₀⁶(16 - (2q + 4))dq = ∫₀⁶(12 - 2q)dq = [12q - q²]₀⁶ = 72 - 36 = 36.ChoiceA(36. Choice A (24) uses incorrect integration limits. Choice C (48)omitsthesquaredterminintegration.ChoiceD(48) omits the squared term in integration. Choice D (64) calculates total revenue minus variable cost instead of producer surplus.

Question 3

In a perfectly competitive market, a firm's marginal cost curve is given by MC=2q+8MC = 2q + 8, where qq is the quantity produced. If the market price is $24 and the firm's fixed costs are $50, what is the firm's economic profit at the profit-maximizing output level?

  1. $78 (correct answer)
  2. $128
  3. $178
  4. $228
Explanation: At profit maximization, P = MC, so $24 = 2q + 8, which gives q = 8. Total cost includes both variable and fixed costs. The variable cost is the integral of MC: VC = q² + 8q = 64 + 64 = $128. Total cost = VC + FC = $128 + $50 = $178. Total revenue = P × q = $24 × 8 = $192. Economic profit = TR - TC = $192 - $178 = 78.ChoiceB(78. Choice B (128) represents variable cost only. Choice C (178)representstotalcost.ChoiceD(178) represents total cost. Choice D (228) incorrectly adds fixed costs twice.

Question 4

A perfectly competitive firm operating in the short run has marginal cost MC=3q+2MC = 3q + 2 and average variable cost AVC=1.5q+2AVC = 1.5q + 2. If the firm is currently producing 8 units and earning zero economic profit, what must be the firm's total fixed cost?

  1. $96 (correct answer)
  2. $112
  3. $128
  4. $144
Explanation: Since the firm produces where P = MC and is producing 8 units, the market price is MC = 3(8) + 2 = $26. At q = 8, AVC = 1.5(8) + 2 = $14, so total variable cost = $14 × 8 = $112. Total revenue = $26 × 8 = 208.Withzeroeconomicprofit,totalcostequalstotalrevenue(208. With zero economic profit, total cost equals total revenue (208), so total fixed cost = $208 - $112 = $96. Choice B represents total variable cost, Choice C uses incorrect cost calculations, and Choice D results from computational errors.

Question 5

In long-run equilibrium in a perfectly competitive market, if a typical firm's minimum efficient scale occurs at 1,000 units with a long-run average cost of $8, and market demand at $8 is 50,000 units, what can be concluded about the market structure?

  1. The number of firms cannot be determined without knowing the industry's total fixed costs and entry barriers
  2. The market will have fewer than 50 firms due to economies of scale advantages for larger producers
  3. The market will have more than 50 firms because some will produce below minimum efficient scale to maintain competitiveness
  4. The market will support exactly 50 firms, each producing at minimum efficient scale with zero economic profit (correct answer)
Explanation: This question tests your understanding of long-run equilibrium in perfectly competitive markets, where economic forces determine both firm size and market structure simultaneously. In perfect competition's long-run equilibrium, firms must produce at their minimum efficient scale to survive. Here's why: if price equals $8 (the minimum long-run average cost), any firm producing above or below 1,000 units would have higher average costs and earn negative economic profits, forcing them to exit or adjust to the efficient scale. With market demand of 50,000 units at $8 and each firm producing exactly 1,000 units at minimum efficient scale, the market supports exactly 50 firms (50,000 ÷ 1,000 = 50). Each firm earns zero economic profit because price equals minimum average cost. This is answer D. Answer A is wrong because perfect competition assumes no entry barriers, and you have all the information needed—minimum efficient scale determines firm size, while market demand determines the total number of firms. Answer B incorrectly suggests fewer than 50 firms, but this would require firms to produce above minimum efficient scale, which isn't sustainable when price equals minimum average cost. Answer C misunderstands competitive equilibrium—firms producing below minimum efficient scale would lose money at the $8 price and exit the market. Remember this key insight: in long-run competitive equilibrium, market demand divided by minimum efficient scale gives you the exact number of firms. The market structure adjusts so all surviving firms operate at their most efficient point.

Question 6

A perfectly competitive, increasing-cost industry is in long-run equilibrium. A new study reveals significant health benefits of its product, leading to a permanent increase in market demand. Compared to the initial long-run equilibrium, the new long-run equilibrium price will be:

  1. higher than the initial price but lower than the short-run price. (correct answer)
  2. equal to the initial long-run equilibrium price.
  3. equal to the new short-run equilibrium price.
  4. lower than the initial long-run equilibrium price due to economies of scale from new entrants.
Explanation: The permanent increase in demand causes the market price to rise in the short run, leading to positive economic profits for existing firms. These profits attract new firms to enter the market. In an increasing-cost industry, the entry of new firms increases the demand for industry-specific inputs, causing input prices to rise. This shifts the cost curves (ATC and MC) for all firms upward. Entry continues until profits are zero again, which occurs at a price equal to the new, higher minimum ATC. This new long-run price is higher than the original price but lower than the peak short-run price that induced entry.

Question 7

A perfectly competitive, constant-cost industry is in long-run equilibrium. The government imposes a per-unit tax of $2 on every unit sold. In the new long-run equilibrium, what is the relationship between the new market price paid by consumers (P2P_2) and the initial market price (P1P_1)?

  1. P_2 = P_1 + \2$ (correct answer)
  2. P_1 < P_2 < P_1 + \2$
  3. P2=P1P_2 = P_1
  4. P_2 > P_1 + \2$
Explanation: The per-unit tax increases both the marginal cost and average total cost for each firm by $2. This causes firms to incur economic losses at the initial price P1P_1. These losses will cause firms to exit the industry. As firms exit, the market supply decreases, and the market price rises. In a constant-cost industry, input prices do not change as the industry contracts or expands, so the long-run industry supply curve is perfectly elastic. The exit process continues until the market price rises by the full amount of the tax, restoring the zero-economic-profit condition for the remaining firms. Thus, the new price P2P_2 will be exactly P_1 + \2$.

Question 8

In the short run, a perfectly competitive firm is producing at an output level where its price is $20, marginal cost is $20, and average total cost is $25. Which of the following statements about efficiency is true for this firm's level of production?

  1. It is allocatively efficient but not productively efficient. (correct answer)
  2. It is productively efficient but not allocatively efficient.
  3. It is both allocatively and productively efficient.
  4. It is neither allocatively nor productively efficient.
Explanation: Allocative efficiency occurs where the value to consumers for the last unit (price) equals the marginal cost of producing it (P = MC). In this case, (20=20 = 20), so the firm is allocatively efficient. Productive efficiency occurs when a good is produced at the lowest possible cost, which is at the minimum of the Average Total Cost (ATC) curve. At the minimum of the ATC curve, MC = ATC. Since MC (20)isnotequaltoATC(20) is not equal to ATC (25), the firm is not producing at its minimum ATC and is therefore not productively efficient.

Question 9

A perfectly competitive market has a demand curve given by QD=5000−50PQ_D = 5000 - 50P. All firms in the industry are identical, with a long-run total cost function LTC=2q3−16q2+40qLTC = 2q^3 - 16q^2 + 40q, where q is the quantity produced by a single firm. What is the total number of firms in this industry in the long-run equilibrium?

  1. 4,600
  2. 4
  3. 575
  4. 1,150 (correct answer)
Explanation: When analyzing long-run equilibrium in perfect competition, you need to find where firms earn zero economic profit and determine how many firms the market can support at that equilibrium. In long-run equilibrium, firms produce where price equals minimum long-run average cost. First, find the long-run average cost function: LRAC=LTCq=2q2−16q+40LRAC = \frac{LTC}{q} = 2q^2 - 16q + 40. To minimize this, take the derivative and set it equal to zero: d(LRAC)dq=4q−16=0\frac{d(LRAC)}{dq} = 4q - 16 = 0, giving q=4q = 4. At this quantity, each firm's minimum LRAC is 2(4)2−16(4)+40=82(4)^2 - 16(4) + 40 = 8. Therefore, the long-run equilibrium price is $8. Next, find total market quantity demanded at this price using $QD=5000−50P=5000−50(8)=4600Q_D = 5000 - 50P = 5000 - 50(8) = 4600 .Sinceeachfirmproduces4unitsinequilibrium,thenumberoffirmsis. Since each firm produces 4 units in equilibrium, the number of firms is 46004=1150\frac{4600}{4} = 1150 $. Answer (A) of 4,600 represents the total market quantity, not the number of firms. Answer (B) of 4 gives you the quantity each individual firm produces, missing the final step of dividing total quantity by firm output. Answer (C) of 575 likely comes from incorrectly dividing 4,600 by 8 (the price) instead of by 4 (the firm's output). Remember: in long-run perfect competition problems, always find the firm's profit-maximizing quantity at minimum average cost, then divide total market demand at that price by individual firm output to get the number of firms.

Question 10

In a perfectly competitive market, which of the following provides the most direct signal for new firms to enter the industry?

  1. The market demand curve shifts to the right, causing the market price to increase.
  2. Existing firms' total revenues exceed their total accounting costs.
  3. The market price is greater than the average variable cost for existing firms.
  4. Existing firms' total revenues exceed their total economic costs. (correct answer)
Explanation: When analyzing market entry decisions in perfect competition, you need to focus on profitability signals that indicate whether entering firms can earn positive economic profits. This distinguishes between mere survival and actual attractive investment opportunities. Option D is correct because when existing firms' total revenues exceed their total economic costs, they're earning positive economic profits. Economic costs include both explicit costs (like wages and rent) and implicit costs (opportunity costs of resources). Positive economic profits signal that resources in this industry are earning above-normal returns compared to their next-best alternative uses, making entry attractive to new firms. Option A is incorrect because while a rightward demand shift and higher prices suggest improved conditions, this alone doesn't guarantee profitability—you need to know the relationship between price and costs. Option B is wrong because accounting profits (revenues minus accounting costs) don't include opportunity costs. A firm might show accounting profits while actually earning below-normal returns when opportunity costs are considered, making entry unattractive. Option C is incorrect because price exceeding average variable cost only ensures existing firms won't shut down in the short run—it doesn't indicate whether entry would be profitable. The key distinction is between accounting profits and economic profits. New firms enter when they expect to earn positive economic profits, not just cover their explicit costs. Remember: positive economic profits are the beacon that attracts new entrants, while zero economic profits represent the long-run equilibrium where entry stops.

Question 11

The demand curve facing a single firm in a perfectly competitive industry is perfectly elastic primarily because:

  1. there are no barriers to entry or exit in the market.
  2. the market demand curve for the product is perfectly elastic.
  3. the firm's product is a perfect substitute for the products of many other firms. (correct answer)
  4. the firm's marginal revenue is equal to the market price.
Explanation: When analyzing perfect competition, the key insight is understanding why individual firms face a horizontal (perfectly elastic) demand curve even though the overall market demand slopes downward. In perfect competition, each firm produces an identical product that consumers view as completely interchangeable with competitors' products. This perfect substitutability means that if one firm raises its price even slightly above the market price, all customers will immediately switch to competitors offering the same product at the lower market price. Conversely, the firm has no incentive to price below the market price since it can sell all it wants at the current market price. This creates a horizontal demand curve at the market price level, making option C correct. Let's examine why the other options miss the mark. Option A incorrectly identifies the cause—while free entry and exit are characteristics of perfect competition, they don't directly explain the perfectly elastic demand curve facing individual firms. Option B contains a fundamental error: the market demand curve is not perfectly elastic; it slopes downward normally. Only individual firms face perfectly elastic demand. Option D describes a result of perfect competition (MR=PMR = P) rather than explaining why the demand curve is horizontal. Study tip: Remember the substitutability principle—perfect competition means perfect substitutes. When you see questions about firm-level demand curves in different market structures, always ask: "How substitutable is this firm's product?" The answer determines the elasticity of demand the firm faces.

Question 12

A firm in a perfectly competitive market has a short-run total cost function of TC=50+4Q+Q2TC = 50 + 4Q + Q^2. Its marginal cost is MC=4+2QMC = 4 + 2Q. If the market price is $24, what is the firm's producer surplus?

  1. $140
  2. $50
  3. $100 (correct answer)
  4. $240
Explanation: Producer surplus questions in perfectly competitive markets require you to find the area above the marginal cost curve and below the market price. Think of producer surplus as the extra benefit firms receive when they can sell at market price while their costs increase gradually with each unit produced. To find producer surplus, you first need the profit-maximizing quantity where MC=PMC = P. Setting the marginal cost equal to the market price: 4+2Q=244 + 2Q = 24, which gives Q=10Q = 10 units. Producer surplus equals the area of the triangle between the price line and the marginal cost curve, from quantity 0 to 10. At Q=0Q = 0, marginal cost is $4. At $Q=10Q = 10 ,marginalcostequalsthepriceof, marginal cost equals the price of 24. This creates a triangle with base = 10 units and height = 24−4=2024 - 4 = 20. The area is 12×10×20=100\frac{1}{2} \times 10 \times 20 = 100. Answer A (140)likelycomesfromincorrectlycalculatingthetriangleareaorincludingfixedcostsinthecalculation.AnswerB(140) likely comes from incorrectly calculating the triangle area or including fixed costs in the calculation. Answer B (50) represents only the fixed cost component, which isn't part of producer surplus. Answer D (240)appearstobethetotalrevenue(240) appears to be the total revenue ( 24×1024 \times 10 $), but producer surplus is the area above marginal cost, not total revenue. Study tip: Always remember that producer surplus is geometric - visualize the triangle above the MC curve and below the price line. Don't confuse it with profit (which subtracts total costs) or revenue (which ignores costs entirely).

Question 13

A firm in a perfectly competitive industry is experiencing losses. The market price is above the firm's minimum average variable cost but below its minimum average total cost. Which of the following is the firm's optimal strategy?

  1. Shut down immediately in the short run and exit the industry in the long run.
  2. Continue to produce in the short run but exit the industry in the long run if conditions do not improve. (correct answer)
  3. Continue to produce in both the short run and the long run, as it is covering variable costs.
  4. Increase its price to cover its average total cost.
Explanation: When analyzing a firm's decision in perfect competition, you need to understand the shutdown rule and distinguish between short-run and long-run strategies. The key is comparing market price to two critical cost thresholds: minimum average variable cost (AVC) and minimum average total cost (ATC). Since the market price exceeds minimum AVC but falls below minimum ATC, the firm is covering all its variable costs plus contributing something toward fixed costs. In the short run, the firm should continue operating because shutting down would mean losing all fixed costs, while operating means losing less than the full amount of fixed costs. This makes continued production the profit-maximizing (or loss-minimizing) choice in the short run. However, in the long run, all costs become variable, and firms cannot sustain losses indefinitely. If market conditions don't improve to allow the firm to cover its full average total cost, it should exit the industry when its fixed commitments expire. Choice A is wrong because immediate shutdown would increase losses in the short run since the firm is covering variable costs. Choice C incorrectly suggests the firm should stay long-term despite ongoing losses—covering variable costs isn't sufficient for long-run viability. Choice D misunderstands perfect competition: individual firms are price-takers and cannot unilaterally raise prices above the market level. Remember this decision framework: if price > minimum AVC, produce in the short run; if price < minimum ATC, plan to exit in the long run unless conditions improve.

Question 14

In a perfectly competitive market in long-run equilibrium, 10,000 units are sold at a price of $50. At this equilibrium, P=MC=min ATCP=MC=\text{min } ATC. If a government regulation forced production to be restricted to 8,000 units, and the price consumers are willing to pay for the 8,000th unit is $60, which of the following would be a consequence?

  1. The market would become more efficient because firms' productive efficiency would increase.
  2. A deadweight loss would be created because consumers' marginal benefit exceeds producers' marginal cost for units between 8,000 and 10,000. (correct answer)
  3. There would be no deadweight loss, as the market would still be characterized by many firms and freedom of entry.
  4. A surplus of 2,000 units would be created in the market because price is above marginal cost.
Explanation: This question tests your understanding of market efficiency and deadweight loss in perfectly competitive markets. When you see a scenario involving government restrictions on output in a competitive market, think about whether the restriction creates inefficiency by preventing mutually beneficial trades. In the original equilibrium, the market operates efficiently with P=MC=min ATC=$50P = MC = \text{min } ATC = \$50 at 10,000 units. When production is restricted to 8,000 units, consumers are willing to pay $60 for the 8,000th unit, but firms' marginal cost remains $50 (since we're still in the same cost structure). This creates a wedge between marginal benefit and marginal cost. For every unit between 8,000 and 10,000, consumers value the product more than it costs to produce (marginal benefit > marginal cost), yet these trades cannot occur due to the restriction. This represents a deadweight loss – a pure welfare loss where potential gains from trade are eliminated. Answer B correctly identifies this efficiency loss. Answer A is wrong because restricting output doesn't improve productive efficiency – firms were already producing at minimum average total cost. Answer C misses the point entirely; having many firms doesn't prevent deadweight loss when output restrictions exist. Answer D confuses the situation by suggesting a surplus of units exists, but the restriction actually creates scarcity – there are fewer units available than consumers want at the market-clearing price. Study tip: Remember that deadweight loss occurs whenever marginal benefit doesn't equal marginal cost. Government interventions that prevent markets from reaching their natural equilibrium typically create these inefficiencies, even in competitive markets.

Question 15

A perfectly competitive industry initially in long-run equilibrium experiences a permanent increase in demand. During the adjustment to the new long-run equilibrium, which sequence of events is most likely to occur?

  1. Existing firms immediately increase capacity to meet new demand, maintaining original price and zero economic profits throughout
  2. Price rises, existing firms increase output and earn positive profits, new firms enter, price falls but remains above original level
  3. Price rises, existing firms increase output and earn positive profits, new firms enter, price falls back to original level (correct answer)
  4. Price rises temporarily, but immediate entry of new firms prevents existing firms from earning positive profits during adjustment
Explanation: When you encounter questions about perfectly competitive markets adjusting to demand changes, focus on the step-by-step process and remember that adjustment takes time—markets don't instantly reach new equilibrium. Here's what happens when demand permanently increases: Initially, the higher demand pushes price above the original equilibrium level. Existing firms respond by moving up their supply curves, increasing output to maximize profits. Since price now exceeds average total cost, these firms earn positive economic profits in the short run. These profits attract new firms to enter the industry. As new firms enter, industry supply increases, which drives price back down. In a perfectly competitive market with constant costs, this process continues until price returns to exactly the original level, where firms again earn zero economic profits. Option A is wrong because firms can't "immediately increase capacity"—they need time to adjust, and price must rise to signal the need for more output. Option B incorrectly suggests the final price remains above the original level, but in constant-cost industries, long-run equilibrium price returns to the original level. Option D is wrong because entry takes time—existing firms definitely earn positive profits during the adjustment period before new competitors arrive. The key insight is that perfectly competitive markets self-correct through the entry/exit mechanism, but this process isn't instantaneous. Remember: short-run profits signal long-run entry, which eventually eliminates those profits by driving price back down to minimum average total cost.

Question 16

A perfectly competitive firm is currently producing its profit-maximizing output. The government introduces a new regulation that requires all firms in the industry to pay a lump-sum annual licensing fee. How will this affect the firm's profit-maximizing output and its short-run supply curve?

  1. Output will increase because the firm must sell more to cover the fee.
  2. Output will decrease, and the supply curve will shift to the left.
  3. Output will not change, but the supply curve will shift to the left.
  4. Output will not change, and the supply curve will not shift. (correct answer)
Explanation: When analyzing how costs affect a perfectly competitive firm's decisions, you need to distinguish between fixed costs and variable costs. A lump-sum licensing fee is a fixed cost—it doesn't change with the quantity produced. In perfect competition, firms maximize profit where marginal revenue equals marginal cost (MR=MCMR = MC). Since the licensing fee is fixed, it doesn't affect marginal cost at any production level. The firm's marginal cost curve remains unchanged, so the profit-maximizing output stays the same. Additionally, a firm's short-run supply curve is simply its marginal cost curve above the shutdown point. Since marginal costs haven't changed, the supply curve doesn't shift either. Option A incorrectly assumes firms increase output to "cover" fixed costs. However, profit maximization depends on marginal analysis, not total costs. Producing more when MR<MCMR < MC would actually reduce profits further. Option B suggests both output and supply decrease, but this would only occur if marginal costs increased, which doesn't happen with fixed costs. Option C correctly identifies that output won't change but wrongly claims the supply curve shifts—remember, the supply curve reflects marginal costs, not fixed costs. The key insight is that fixed costs affect total profit but not production decisions. While the firm earns less profit (or potentially operates at a loss), it continues producing the same quantity as long as it covers variable costs. Study tip: Always ask whether a cost change affects marginal cost. If not, optimal output remains unchanged in competitive markets.

Question 17

Consider a perfectly competitive, constant-cost industry in long-run equilibrium. A new technology becomes available that lowers the average and marginal costs of production for any firm that adopts it. If some firms adopt the new technology, what will happen in the long run?

  1. Firms that do not adopt the technology will continue to operate alongside the firms that do.
  2. Only the firms that adopt the technology will remain, and they will earn long-run economic profits.
  3. The market price will remain the same, but the output of firms that adopt the technology will increase.
  4. All firms that survive will adopt the technology, and the market price will decrease. (correct answer)
Explanation: This question tests your understanding of how technological innovation affects perfectly competitive markets in long-run equilibrium. When you see technology adoption scenarios, think about the adjustment process and what forces drive firms toward equilibrium. In a perfectly competitive market, firms are price-takers earning zero economic profit in long-run equilibrium. When new cost-reducing technology becomes available, it creates a temporary advantage for adopting firms. These firms can now produce at lower costs while selling at the same market price, earning short-run economic profits. However, these profits attract new firms to enter the industry, and existing firms have strong incentives to adopt the technology to remain competitive. As more firms adopt the technology and new efficient firms enter, market supply increases, driving down the market price. Firms that don't adopt the technology face a squeeze: they maintain their old, higher cost structure while the market price falls, eventually forcing them into losses and out of the market. In the new long-run equilibrium, all surviving firms will have adopted the technology (making D correct), and the market price will settle at the new, lower minimum average cost. Option A is wrong because high-cost firms cannot survive when price falls below their average cost. Option B incorrectly suggests firms earn long-run economic profits, but perfect competition drives profits to zero. Option C is wrong because increased supply from technology adoption will decrease market price, not keep it constant. Remember: In perfect competition, cost-reducing innovations eventually benefit consumers through lower prices, not firms through sustained profits.

Question 18

A perfectly competitive, increasing-cost industry is in long-run equilibrium. The government introduces a per-unit subsidy of $5 for every unit produced. What is the most likely outcome in the new long-run equilibrium?

  1. The market price paid by consumers will decrease by more than $5.
  2. The market price paid by consumers will decrease by exactly $5.
  3. The market price paid by consumers will decrease by less than $5. (correct answer)
  4. The market price paid by consumers will remain the same, but industry output will increase.
Explanation: When analyzing subsidy effects in perfectly competitive markets, you need to consider both short-run adjustments and long-run industry characteristics. The key insight here is that this is an increasing-cost industry, which means input prices rise as industry output expands. In the short run, the $5 subsidy shifts each firm's marginal cost curve down by $5, causing them to increase output. Market supply increases, driving down the consumer price. However, this isn't the end of the story. The lower consumer price and higher producer profits attract new firms to enter the industry. As the industry expands in this increasing-cost setting, input prices rise due to greater demand for scarce resources (land, specialized labor, etc.). These rising input costs shift firms' cost curves back up, though not all the way to their original position. The new long-run equilibrium occurs when economic profits return to zero, but at a higher industry output level. The final consumer price will be lower than the original price, but the decrease will be less than the full $5 subsidy because rising input costs partially offset the subsidy's effect. Answer A is wrong because increasing input costs prevent the full subsidy from passing through to consumers. Answer B incorrectly assumes constant costs, where the full subsidy would pass through. Answer D is wrong because consumer prices must fall to clear the increased market output - the subsidy doesn't just disappear. Study tip: Remember that in increasing-cost industries, expansion drives up input prices, which always dampens the effects of subsidies and taxes compared to constant-cost scenarios.

Question 19

Suppose the property taxes for all businesses in a perfectly competitive, constant-cost industry are significantly reduced. These taxes are a component of firms' fixed costs. Starting from a position of long-run equilibrium, what is the effect of this change in the new long-run equilibrium?

  1. The market price and industry output will remain unchanged because marginal cost is unaffected.
  2. The market price will decrease, and the industry output will increase. (correct answer)
  3. The market price will decrease, but industry output will remain the same.
  4. The market price will remain the same, but profits for existing firms will permanently increase.
Explanation: This question tests your understanding of how changes in fixed costs affect perfectly competitive markets in the long run. When you see questions about tax changes or other cost shifts in perfect competition, always consider both short-run and long-run effects. When property taxes (a fixed cost) are reduced, firms' average total costs decrease while marginal costs remain unchanged. In the short run, this creates economic profits for existing firms since the market price stays the same but costs are lower. However, in a perfectly competitive market, economic profits attract new firms to enter the industry. As new firms enter, the market supply curve shifts rightward, driving down the market price. This process continues until economic profits return to zero—the hallmark of long-run equilibrium in perfect competition. The final result is a lower market price and higher industry output due to more firms operating in the market. Answer A is incorrect because while marginal cost is unaffected, the entry of new firms still changes market outcomes. The reduction in fixed costs enables more firms to operate profitably at lower price levels. Answer C misses that industry output increases when new firms enter the market, even though each individual firm produces the same quantity. Answer D reflects a common misconception—that firms can maintain permanent economic profits in perfect competition. The entry of new firms always eliminates these profits in the long run. Remember: In perfectly competitive markets, any change that affects profitability will trigger entry or exit, ultimately restoring zero economic profits while changing market price and total output.

Question 20

An entrepreneur is considering leaving her job as a software engineer, where she earns $120,000 per year, to start a small farm that operates in a perfectly competitive market. She estimates her annual accounting costs for the farm (seeds, rent, hired labor) will be $80,000. If the farm industry is in long-run equilibrium, what is the expected annual total revenue for her farm?

  1. $200,000 (correct answer)
  2. $80,000
  3. $120,000
  4. $40,000
Explanation: In long-run equilibrium, perfectly competitive firms earn zero economic profit. Economic profit equals total revenue minus all economic costs. Economic costs include explicit (accounting) costs and implicit (opportunity) costs. The explicit costs are $80,000. The implicit cost is the entrepreneur's forgone salary of $120,000. For economic profit to be zero, total revenue must cover both: Total Revenue = Explicit Costs + Implicit Costs = $80,000 + $120,000 = $200,000. This revenue would yield an accounting profit of $120,000, which exactly compensates her for her lost salary.