Microeconomics for Business 2078 Board Question Paper

Reason: The Production Possibility Curve (PPC) is downward sloping and concave to the origin due to the Law of Increasing Marginal Opportunity Cost (or increasing Marginal Rate of Transformation, $MRT_{xy}$).

As more units of Good X are produced, increasingly larger amounts of Good Y must be sacrificed ($MRT_{xy} = \Delta Y / \Delta X \uparrow$) because productive resources are specialized and not equally efficient in the production of both commodities.

Four factors that cause a rightward (outward) shift in the market demand curve are:

1. Increase in Consumer Income (for normal goods).
2. Rise in the Price of Substitute Goods (e.g., rise in coffee price shifts tea demand rightward).
3. Favorable Changes in Tastes, Habits, and Fashion.
4. Growth in Population and Number of Buyers in the market.

Based on the sign and magnitude of Income Elasticity of Demand ($e_y$):

1. Mobile Set ($e_y = +2.3$): Since $e_y > 1$, it is a Luxury / Superior Good (demand expands more than proportionately as income rises).
2. Potato ($e_y = -0.6$): Since $e_y < 0$, it is an Inferior Good (demand contracts as consumer income increases).
3. Salt ($e_y = 0$): Since $e_y = 0$, it is a Strict Necessity / Neutral Good (consumption is completely insensitive to changes in income).

Four core assumptions of indifference curve analysis:

1. Rationality: The consumer is rational and seeks to maximize total utility subject to budget constraints.
2. Ordinal Utility: Utility is qualitative and can be ranked ($1^{\text{st}}, 2^{\text{nd}}, 3^{\text{rd}}$), but cannot be measured cardinally.
3. Diminishing Marginal Rate of Substitution ($MRS_{xy}$): The consumer gives up progressively fewer units of $Y$ for each additional unit of $X$.
4. Consistency and Transitivity of Choice: If bundle $A > B$ and $B > C$, then bundle $A > C$.

Step 1: Formula for Degree of Economies of Scope ($SC$)

$$SC = \frac{C(Q_A) + C(Q_B) - C(Q_A, Q_B)}{C(Q_A, Q_B)}$$

Step 2: Calculation

$$SC = \frac{400,000 + 200,000 - 500,000}{500,000} = \frac{600,000 - 500,000}{500,000} = \frac{100,000}{500,000} = \mathbf{0.20 \text{ or } 20\%}$$

Interpretation: Since $SC = 0.20 > 0$, economies of scope exist. Jointly producing products A and B reduces total cost by 20% compared to standalone independent production.

Explicit costs are actual out-of-pocket cash payments made to external suppliers of productive inputs. Four examples include:

1. Wages and salaries paid to hired workers.
2. Payments for raw materials and semi-finished goods.
3. Rent paid for factory premises or office buildings.
4. Utility bills (electricity, water, internet) and interest paid on borrowed bank loans.

Mathematical Relationship:

$$MR = AR \left(1 - \frac{1}{|E_p|}\right)$$

Where $AR = \text{Price } (P)$ and $E_p$ is price elasticity of demand.

Three Strategic Implications:

1. If $|E_p| > 1$ (Elastic Demand), then $MR > 0$.
2. If $|E_p| = 1$ (Unitary Elasticity), then $MR = 0$ (Total Revenue is maximized).
3. If $|E_p| < 1$ (Inelastic Demand), then $MR < 0$.

Firms in an oligopolistic industry form a cartel (explicit collusive agreement) for the following primary reasons:

1. To Eliminate Price Wars: Suppresses ruinous price competition among rival firms.
2. To Maximize Joint Profits: Functions as a collective monopoly to restrict industry output and charge higher monopoly prices.
3. To Restrict Entry: Creates collective barriers preventing new competitors from entering the market.

Interest rates differ across borrowers and financial markets due to:

1. Differences in Risk of Default: Riskier borrowers are charged higher risk premiums.
2. Differences in Loan Maturity / Duration: Longer-term loans carry higher liquidity risk.
3. Differences in Collateral Quality: Secured loans have lower interest rates than unsecured personal loans.
4. Administrative and Transaction Costs: Small, retail loans entail higher processing costs per rupee.

Step 1: General Equation of Iso-Cost Line

$$wL + rK = C$$

$$100L + 50K = 2000$$

Step 2: Find Intercepts

• Labor Intercept ($L$ on X-axis): $\frac{C}{w} = \frac{2000}{100} = \mathbf{20 \text{ units}}$
• Capital Intercept ($K$ on Y-axis): $\frac{C}{r} = \frac{2000}{50} = \mathbf{40 \text{ units}}$

Step 3: Slope of Iso-Cost Line

$$\text{Slope} = -\frac{w}{r} = -\frac{100}{50} = \mathbf{-2}$$

Nature of Business Economics

1. Microeconomic in Character: Focuses on decision-making at the level of the individual business enterprise.
2. Normative Science: Suggests prescriptive courses of action (“what ought to be done”) rather than purely descriptive economics (“what is”).
3. Pragmatic and Applied: Bridges abstract theoretical economic models with messy, real-world commercial operations.
4. Macroeconomic Environment Awareness: Recognizes how aggregate factors (monetary policy, exchange rates, taxation) frame business boundaries.

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Scope of Business Economics

1. Demand Forecasting & Market Estimation: Projecting future sales volumes across product lines.
2. Production & Cost Optimization: Determining input combinations that minimize average cost.
3. Price & Output Strategy: Formulating mark-up, differential, and promotional pricing models.
4. Profit & Risk Planning: Measuring break-even volume and hedging financial uncertainty.
5. Capital Budgeting: Allocating investment funds to high-yielding projects using NPV and IRR.

1. Concept of Economic Efficiency

Economic Efficiency is an ideal market state where resources are allocated in a manner that maximizes net social surplus (Consumer Surplus + Producer Surplus), such that no individual can be made better off without making someone else worse off (Pareto Optimality).

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2. Dual Dimensions of Economic Efficiency:

(a) Productive (Technical) Efficiency:

• Achieved when goods are produced at the lowest possible unit cost.
• Condition: Output is produced where price equals the minimum of average total cost:
  $$\text{Price} = \min ATC$$

(b) Allocative Efficiency:

• Achieved when the mix of goods produced corresponds exactly to consumer preferences.
• Condition: Price (marginal benefit to society) equals marginal cost (opportunity cost of resources):
  $$P = MC$$

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3. Measuring Economic Efficiency

1. Deadweight Loss ($DWL$): Quantifies the loss of total welfare caused by monopoly power, tariffs, or price ceilings.
2. Consumer and Producer Surplus: Efficiency is measured by the maximization of Total Surplus ($CS + PS$).
3. Incremental Capital-Output Ratio (ICOR): Measures the productivity of investment.

Given Total Product:

$$Q = 14L + 7L^2 - L^3$$

Derive Marginal Product ($MP$) and Average Product ($AP$):

• $MP = \frac{dQ}{dL} = 14 + 14L - 3L^2$
• $AP = \frac{Q}{L} = 14 + 7L - L^2$

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Part (a): Labor where Total Product ($TP$) is Maximum

$TP$ reaches its peak when Marginal Product equals zero ($MP = 0$):

$$14 + 14L - 3L^2 = 0 \iff 3L^2 - 14L - 14 = 0$$

Using the quadratic formula $L = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$:

$$L = \frac{14 \pm \sqrt{(-14)^2 - 4(3)(-14)}}{2(3)} = \frac{14 \pm \sqrt{196 + 168}}{6} = \frac{14 \pm \sqrt{364}}{6} = \frac{14 \pm 19.079}{6}$$

Since labor must be positive:

$$L = \frac{14 + 19.079}{6} = \frac{33.079}{6} \approx \mathbf{5.51 \text{ units}}$$

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Part (b): Labor where Marginal Product ($MP$) is Maximum

$MP$ reaches its peak where its derivative equals zero:

$$\frac{d(MP)}{dL} = 14 - 6L = 0 \implies 6L = 14 \implies L = \frac{14}{6} = \mathbf{2.33 \text{ units}}$$

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Part (c): Labor where Average Product ($AP$) is Maximum

$AP$ reaches its peak where its derivative equals zero (or where $AP = MP$):

$$\frac{d(AP)}{dL} = 7 - 2L = 0 \implies 2L = 7 \implies L = \frac{7}{2} = \mathbf{3.50 \text{ units}}$$

Incremental Cost Pricing

Concept: Incremental Cost Pricing is a managerial decision rule that sets prices by comparing the additional total cost (incremental cost) of taking an executive decision (e.g., accepting a special export order, introducing a new product line) against the additional total revenue (incremental revenue) generated by that decision.

Decision Rule: Accept the decision/order if:

$$\Delta TR > \Delta TC \quad (\text{Incremental Revenue} > \text{Incremental Cost})$$

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Illustrative Business Example:

A garment factory in Biratnagar produces 8,000 shirts per month with total capacity of 10,000 shirts.

• Existing Selling Price = Rs. 800 per shirt.
• Variable Cost = Rs. 400 per shirt.
• Fixed Overhead = Rs. 1,600,000 per month (Rs. 200 per shirt at current output).
• Total Cost per shirt = Rs. 600.

An exporter offers to buy 2,000 additional shirts at a discounted price of Rs. 500 per shirt.

• Conventional Costing View: Reject, because Rs. 500 is below total cost of Rs. 600.
• Incremental Costing View:
  • Incremental Revenue: $2,000 \times 500 = \text{Rs. } 1,000,000$.
  • Incremental Cost (only variable costs since fixed overhead is already sunk): $2,000 \times 400 = \text{Rs. } 800,000$.
  • Net Incremental Profit: $1,000,000 - 800,000 = \mathbf{+\text{Rs. } 200,000}$.

Conclusion: The firm should accept the special order because it yields Rs. 200,000 in incremental profit.

Keynesian Motives for Demand for Money

According to John Maynard Keynes (The General Theory, 1936), people hold liquid money balances for three distinct motives:

1. Transactions Motive ($L_1$):

   • Money held for bridge-the-gap daily personal expenditures and business operational disbursements.
   • Depends primarily on the level of national/personal income:
     $$M_t = f(Y)$$

2. Precautionary Motive ($L_1$):

   • Money held as a safety cushion for sudden emergency needs (medical emergencies, unexpected business disruptions, natural disasters).
   • Also depends directly on income:
     $$M_p = f(Y)$$

3. Speculative Motive ($L_2$):

   • Money held to take advantage of market movements in security prices and bond interest rates.
   • Inversely related to the rate of interest:
     $$M_{sp} = f(r)$$
   • At high interest rates, people hold bonds; at very low rates, they hold cash anticipating interest rate rises.
   • At a rock-bottom rate, the demand curve becomes infinitely elastic (The Liquidity Trap).

Step 1: Formulas

• $TFC = TC \text{ when } Q = 0 = \mathbf{40}$ (constant for all output levels).
• $TVC = TC - TFC$
• $AFC = TFC / Q$
• $AVC = TVC / Q$
• $ATC = TC / Q = AFC + AVC$
• $MC = TC_n - TC_{n-1}$

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Step 2: Complete Cost Table

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Observations:

1. $AFC$ declines continuously as output expands (rectangular hyperbola).
2. $AVC$ reaches its minimum of 9.25 at $Q = 4$ and rises thereafter.
3. $ATC$ reaches its minimum of 18.00 at $Q = 5$.
4. $MC$ cuts $AVC$ and $ATC$ at their respective minimum points.

1. Definition of Price Effect

The Price Effect measures the total change in the consumer’s optimal consumption of a commodity resulting from a change in the price of that commodity, holding monetary income and the prices of all other goods constant.

$$\text{Price Effect } (PE) = \text{Substitution Effect } (SE) + \text{Income Effect } (IE)$$

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2. Decomposition Mechanism (Hicksian Approach)

When the price of Good $X$ falls ($P_x \downarrow$):

1. Substitution Effect ($SE$): Good $X$ becomes relatively cheaper than Good $Y$. The consumer substitutes $X$ for $Y$, moving along the original indifference curve ($IC_1$) to maintain the same real utility. The substitution effect is always negative (buying more of the cheaper good).
2. Income Effect ($IE$): The price reduction increases the consumer’s real purchasing power. For a normal good, this rise in real income induces the consumer to buy even more units of $X$.

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3. Step-by-Step Graphical Decomposition:

• Initial Equilibrium: Budget line $AB$ is tangent to $IC_1$ at point $E_1$ with consumption $X_1$.
• New Budget Line: Fall in $P_x$ rotates the budget line outward to $AB_1$, reaching a higher indifference curve $IC_2$ at point $E_2$ with consumption $X_2$.
  $$\text{Total Price Effect} = X_1 X_2$$
• Compensating Variation in Income: Reduce the consumer’s nominal income hypothetically (shift $AB_1$ downward parallel to $CD$) until it is tangent to the original indifference curve $IC_1$ at point $E_3$.
  • Substitution Effect: Movement from $E_1$ to $E_3$ along $IC_1 = X_1 X_3$.
  • Income Effect: Movement from $E_3$ on $IC_1$ to $E_2$ on $IC_2 = X_3 X_2$.
• Since both $SE$ and $IE$ reinforce each other in the same direction for normal goods, the demand curve is downward sloping (Law of Demand).

1. Characteristics of Monopolistic Competition

Developed by Edward Chamberlin, monopolistic competition combines elements of monopoly and competition:

1. Large Number of Sellers and Buyers
2. Product Differentiation: Goods are close, but not perfect, substitutes (via branding, packaging, features).
3. Free Entry and Exit of firms in the long run.
4. Selling Costs: Heavy expenditure on advertising and sales promotion.
5. Downward Sloping, Elastic Demand Curve: Firms possess slight price-setting discretion.

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2. Short-Run Price and Output Determination

A firm maximizes short-run profit where:

$$MR = SMC \quad \text{and } SMC \text{ cuts } MR \text{ from below}$$

• Supernormal Profits: When $P > ATC$ at equilibrium output.
• Normal Profits: When $P = ATC$.
• Losses: When $AVC < P < ATC$.

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3. Long-Run Price and Output Determination

Due to free entry and exit:

• If short-run supernormal profits exist, new firms enter, reducing the market share of existing firms and shifting individual demand curves ($AR$) leftward until:
  $$P = LAC \quad \text{and} \quad MR = LMC$$
• In the long run, firms earn only Normal Profits, but operate with Excess Capacity because $P = LAC$ occurs to the left of the minimum point of $LAC$.

Part (a): Arc Price Elasticity Calculations

Formula:

$$E_p = \left|\frac{Q_2 - Q_1}{P_2 - P_1} \times \frac{P_1 + P_2}{Q_1 + Q_2}\right|$$

1. Movement from B to D:

   • Point B: $P_1 = 8, Q_1 = 20$; Point D: $P_2 = 4, Q_2 = 60$$E_p = \left|\frac{60 - 20}{4 - 8} \times \frac{8 + 4}{20 + 60}\right| = \left|\frac{40}{-4} \times \frac{12}{80}\right| = 10 \times 0.15 = \mathbf{1.50}$$

2. Movement from D to B:

   • Point D: $P_1 = 4, Q_1 = 60$; Point B: $P_2 = 8, Q_2 = 20$$E_p = \left|\frac{20 - 60}{8 - 4} \times \frac{4 + 8}{60 + 20}\right| = \left|\frac{-40}{4} \times \frac{12}{80}\right| = 10 \times 0.15 = \mathbf{1.50}$$ (The arc method provides an invariant, symmetric measure regardless of movement direction).

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Part (b): Revenue Schedule

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Part (c): Strategic Relationship between $E_p$ and $TR$

1. Elastic Demand ($E_p > 1$, Points A to C): Price reduction increases $TR$ ($MR > 0$).
2. Unitary Elastic Demand ($E_p = 1$, between C and D): $TR$ reaches its maximum of Rs. 240 ($MR = 0$).
3. Inelastic Demand ($E_p < 1$, Points D to E): Price reduction decreases $TR$ ($MR < 0$).