AP MICRO Mistake Review
Firm Shutdown Conditions
The firm will shut down if the price falls below the minimum Average Variable Cost (AVC)
According to the Shut Down Rule, if Price falls below the Minimum AVC in the Short Run, the firm must shut down.
Explanation: If the firm cannot pay variable costs, it has no means of remaining operational.
Tax Revenue Calculations
Tax revenue to the government is determined by the equation:
Tax Revenue = Per-Unit Tax × Quantity Sold (after tax is imposed).
This can be visualized as the distance between the possible supply curves of S1 and S2, corresponding to a rectangle that represents the tax revenue.
Market Structures and Pricing Power
The demand curve for a monopolistically competitive firm is downward sloping due to product differentiation, meaning:
Products offered by different firms are similar yet not perfect substitutes.
This product differentiation grants each firm a small degree of market power, enabling it to influence the price of its specific product.
Perfect Price Discrimination
Perfect Price Discrimination occurs when a firm charges each customer their maximum willingness to pay.
Result: The monopolist captures all consumer surplus.
Allocative Efficiency: Achieved when price equals marginal cost, expressed as:
Average Tax Rate (ATR) Calculation
The Average Tax Rate (ATR) is calculated using the formula:
Example: Given that the ATR for an income of 120,000 is less than that of 100,000 (0.4 < 0.5), conclusion: C is correct.
Total Revenue Test
Overview of how Total Revenue (TR) varies with price changes based on demand elasticity:
Inelastic Demand: (Price Sensitive)
Consumers buy roughly the same quantity regardless of price changes (e.g., medicine, gas).
Price Up → Revenue Up
Price Down → Revenue Down
Elastic Demand: (Price Sensitive)
Consumers drastically change buying habits according to prices (e.g., luxury items, coffee).
Price Up → Revenue Down
Price Down → Revenue Up
Conclusion: If TR seeks to increase, price decreases, and revenue rises in the Elastic Demand Range.
Utility Maximization
To maximize utility, allocate spending from lower marginal utility per dollar (apples) to a higher marginal utility per dollar (candy bars).
Strategy: Purchase fewer apples and more candy bars as it maximizes overall utility.
Marginal Revenue Product of Labor (MRPL) Analysis
Given: MRPL = $15/hour , where MRPL is calculated as:
Comparison against Marginal Cost of Labor (MCL): MCL = $20/hour
Conclusion: Since MRPL = $15/hour is less than MCL = $20/hour, it's indicated that the productivity of the last worker is less than the cost of employing that worker. Therefore, fewer workers should be employed.
Monopoly Inefficiencies
Monopolies are deemed inefficient relative to perfectly competitive firms because: -(A) they produce output where average total cost exceeds average revenue. -(B) they typically produce less output than is socially desirable. -(C) they charge prices greater than marginal cost.
Correct Choice: (D) indicates monopolies always price above marginal cost (MC).
Pollution and Economic Efficiency
Scenario: A chemical plant pollutes a river, impacting a nearby town's water supply.
Economic Principle: Pollution should be reduced until:
(A) the marginal benefit from cleaner water equals the marginal cost of making the water cleaner.
Conclusion: The socially optimal point is where MB = MC.
Total Cost Calculation
Total cost (TC) is found by summing up all marginal costs (MC) of produced quantities and fixed costs.
Marginal Cost (MC) refers to the additional cost of producing one more unit.
Firm's Pricing Strategy
Given that a firm is a price taker, it can sell any unit of output for $20.
Profit calculation for selling 100 units: profit equals $0 due to perfect competition.
Marginal Revenue (MR) for the 101st unit is $20, with marginal cost at $18, resulting in:
Marginal \ Profit = MR - MC = 20 - 18 = $2
Therefore, producing and selling the 101st unit will increase total profit by $2.
Impact of Wages and Supply
Response to an increase in supply (shift right) causes wages to decrease as seen in work arrangements, not necessarily leading to unemployment increase.
Elastic Range in Revenue Test
In the Elastic Range of the Total Revenue Test, a price decrease leads to an increase in total revenue (TR).
Efficient calculation of ATC represented as:
For Average Product of Labor (APL) equals 5 when 10 units produced (10/5), showcasing that there are two workers employed.
Production Efficiency and Opportunities
Identifying the scenario when Question (12) states Price Makers do not produce at allocative efficiency verifies that monopolists charge more than marginal cost (MC).
Demand-Supply Adjustments
Market adjustments occur when conditions are not at equilibrium, illustrating that demand shifts can lead to price decreases and quantity supplied adjustments over time.
Market Dynamics and Price Equilibrium
Any price setting not at equilibrium leads to natural market movements towards equilibrium, barring external factors impacting market dynamics.
Monopolistically Competitive Pricing Structure
In monopolistic competition, average revenue measures revenue obtained per unit sold. Therefore, average revenue cannot exceed price levels.
Income Effects on Demand
Income Effect: An increase in income leads to increased demand for normal goods, whereas a decrease results in decreased demand.
Conversely, for inferior goods, demand increases as income decreases.
Substitution Effect: A rise in price for a good causes consumers to substitute it with relatively cheaper alternatives, leading to decreased quantity demanded. This effect is invariably negative with price changes.
Costs and Outputs for Competitive Firms
Given the total output of 20 units, solutions for total cost and total fixed cost will be assessed using:
Total Cost = Average Total Cost × Quantity.
With Average Total Cost intersecting at $6 and quantity fixed to 20 units.
Total Fixed Cost is determined by the difference between ATC and AVC multiplied by quantity.
Marginal Revenue Product Analysis
Calculation of MRP based on labor:
If price increases, MRP consequently rises, hence correct answer should align with these economic forecasts.
Governmental Welfare Programs Impact
A welfare program taxing high-income earners to redistribute revenue to low-income citizens is analyzed, finding:
Answer is (B): Decreased income inequality
Marginal Analysis of Labor Productivity
For the twelfth worker:
Profit determination as is crucial for concluding the contribution profit dynamics.
Answer (C): Profit increase of this worker equates to optimal contributions to the workplace's output.
Income Effect
Consumers will buy more beef (normal good) when incomes increase.
Less beef is purchased when the price increases due to income limitation.
Consumer Behavior
A decrease in soft drink price increases purchasing power → more computer apps bought (income effect).
If a good's price rises, consumers may opt for cheaper substitutes, affecting overall consumption.
Market Equilibrium
Hedlund: Demand for caps exceeds supply at $9, leading to imports for equilibrium at 11 million caps.
Market demand for private goods: horizontal summation of individual demands.
Supply Determinants
Increased wages of workers in chocolate factories decreases supply.
Reduced resource costs lead to increased supply.
Demand Elasticity
Demand for milk is inelastic between $5-$11 (total revenue test indicates price and revenue rise together).
Loanable Funds Market
Equilibrium interest rate is 7% with 600 quantity of loans due to matching demand and supply.
Monopoly Pricing
Profit-maximizing output exists in the elastic range (0-Q2).
A monopoly producing below socially optimal output incurs losses; requires government subsidy to sustain production.
Market Forces and Externalities
Higher prices of inputs decrease both producer and consumer surplus (e.g., sport peppers for hot dogs).
An increase in supply of soybeans due to lower resource costs can disrupt equilibrium and affect prices.
Deadweight Loss
Occurs when market fails to produce efficient quantity (e.g., monopolies, positive/negative externalities).
Government-imposed prices may create deadweight loss if set inefficiently and not effective.