CENEVAL EGEL Plus Economía (EGEL Plus ECONO)

A consumer has the utility function U(X, Y) = X^0.5 × Y^0.5. The price of X is MXN 10, the price of Y is MXN 20, and income is MXN 400. What is the utility-maximizing bundle?

• AX = 20, Y = 10
• BX = 10, Y = 20
• CX = 25, Y = 7.5
• DX = 40, Y = 0

A consumer's utility function is U(X, Y) = X^0.4 × Y^0.6. What is the marginal rate of substitution MRS = MUx / MUy at X = 2 and Y = 6?

• A1.50
• B2.00
• C3.00
• D0.67

Market demand for a crop is Q = 120 - 3P. What is the point price elasticity of demand at P = 20?

• A-0.50
• B-0.33
• C-1.00
• D-3.00

When household income rises from MXN 10,000 to MXN 12,000 a month, the quantity demanded of good Z rises from 50 to 55 units. How is good Z classified?

• AInferior good, income elasticity of -0.50
• BLuxury good, income elasticity of +2.00
• CGiffen good, income elasticity of -1.00
• DNormal necessity, income elasticity of +0.50

The cross-price elasticity of demand for good X with respect to the price of good Y is +0.75. What does this indicate?

• AX and Y are substitutes
• BX and Y are complements bought in fixed proportions
• CX and Y are independent, because the value is below 1
• DX and Y are inferior goods, because the sign is positive

How does the Hicksian (compensated) demand function differ from the Marshallian (ordinary) demand function?

• AHicksian demand holds money income constant; Marshallian holds utility constant
• BHicksian demand holds utility constant, so it shows only the substitution effect
• CHicksian demand applies only to Giffen goods, and Marshallian only to normal goods
• DHicksian demand curves slope upward, and Marshallian demand curves slope downward

According to the Slutsky equation, when the price of a normal good rises, how do the substitution and income effects act?

• AThe substitution effect reduces consumption, but the income effect raises it and offsets…
• BThe substitution effect is zero, and the whole change comes from the income effect
• CBoth reduce the quantity demanded
• DThe income effect raises consumption because consumers feel richer when prices rise

A regulator raises the price of electricity and wants to measure the welfare loss. Which statement correctly defines compensating variation (CV) and equivalent variation (EV)?

• ACV is the income removed at the initial prices; EV is the income added at the new prices
• BCV uses the original prices, while EV is the area under the Marshallian demand curve
• CCV and EV are always equal, whatever the consumer's utility function
• DCV: income at new prices to restore old utility; EV: income removed at old prices

A consumer lives for two periods and maximizes U = ln(C1) + β ln(C2). The real interest rate is r. What condition characterizes optimal consumption?

• AC2 / C1 = β(1 + r)
• BC2 / C1 = (1 + r) / β
• CC1 + C2 = β(1 + r)
• DC1 / C2 = β(1 + r)

What does the Weak Axiom of Revealed Preference (WARP) require?

• AThe consumer always chooses the bundle with the lowest total outlay
• BIf A is chosen when B is affordable, B is never chosen when A is affordable
• CIndifference curves must be linear, with constant marginal rates of substitution
• DThe consumer must buy the same bundle whatever prices and income are

A firm's production function is Q = 15 K^0.35 L^0.65. What returns to scale does it show?

• AIncreasing, because total factor productivity is 15
• BDecreasing, because capital's exponent is below 0.50
• CConstant, because the exponents sum to 1
• DDecreasing, because labor's exponent exceeds capital's

In the long run, what condition characterizes the cost-minimizing combination of labor (L) and capital (K), given the wage w and rental rate r?

• AMPL × w = MPK × r
• BMPL / r = MPK / w
• CMPL + MPK = w + r
• DMPL / w = MPK / r

A plant's production function is Q = K^0.5 L^0.5. The wage is MXN 10 and the rental rate of capital is MXN 40. What is the minimum cost of producing Q = 100?

• AMXN 4,000, with K = 50 and L = 200
• BMXN 2,000, with K = 25 and L = 100
• CMXN 5,000, with K = 100 and L = 100
• DMXN 8,000, with K = 80 and L = 320

A competitive firm's short-run total cost is TC = 200 + 10Q + 2Q². What are its AVC and MC, and below what price should it shut down?

• AAVC = 200/Q + 10, MC = 10 + 2Q; shut down below MXN 20
• BAVC = 10 + 2Q, MC = 10 + 4Q; shut down below MXN 10
• CAVC = 10 + 4Q, MC = 10 + 2Q; it never needs to shut down
• DAVC = 10 + 2Q, MC = 10 + 4Q; shut down below MXN 200

In cost analysis, what does a firm's minimum efficient scale (MES) refer to?

• AThe output level that maximizes the firm's total revenue
• BThe smallest plant size that environmental permits allow
• CThe smallest output at which long-run average cost is at its minimum
• DThe output at which average variable cost equals average fixed cost

A perfectly competitive firm faces a price of MXN 24. Its short-run total cost is TC = 200 + 4Q + Q². What should it do?

• AProduce 12 units and earn an economic profit of MXN 44
• BProduce 10 units but shut down now, since the loss is MXN 100
• CProduce 8 units, where it just breaks even with zero profit
• DProduce 10 units and keep operating at a MXN 100 loss

In a competitive industry of identical firms, each firm's long-run cost is LTC = 100Q - 10Q² + Q³. What are each firm's output, the price and the economic profit in long-run equilibrium?

• Aq = 5, P = MXN 75, profit zero
• Bq = 10, P = MXN 100, profit MXN 250
• Cq = 5, P = MXN 50, loss of MXN 50
• Dq = 4, P = MXN 84, profit zero

A monopoly faces inverse demand P = 100 - Q and a constant marginal cost of MXN 20, with no fixed costs. What are its profit and the deadweight loss?

• AProfit MXN 1,200; deadweight loss MXN 400
• BProfit MXN 1,600; deadweight loss MXN 800
• CProfit MXN 800; deadweight loss MXN 1,600
• DProfit MXN 2,400; no deadweight loss

A patent-holding drug maker faces a price elasticity of demand of -2.5 at its profit-maximizing price. What is its Lerner index?

• A0.25
• B0.60
• C0.40
• D2.50

What happens when a monopoly practices first-degree (perfect) price discrimination?

• AConsumer surplus is maximized, and producer surplus falls to zero
• BDeadweight loss is maximized, because consumers pay different prices
• COutput falls below the single-price monopoly level
• DIt captures all consumer surplus and produces the efficient output

A software firm practices third-degree price discrimination between students (|ε| = 3.0) and companies (|ε| = 1.5). How does it set prices?

• AIt charges companies more, because their demand is less elastic
• BIt charges students more, because their demand is more elastic
• CIt charges both groups the same price
• DIt serves only students and drops the corporate segment

What defines a natural monopoly, and what happens if a regulator imposes marginal-cost pricing?

• ARising marginal costs at all output levels; P = MC yields windfall profits
• BFalling average cost over the market; P = MC leaves P < ATC and losses
• CHigh variable costs and no fixed capital; P = MC breaks antitrust law
• DConstant average costs; P = MC then creates multiple equilibria

Two identical firms compete à la Cournot with inverse demand P = 120 - (q1 + q2) and marginal cost MXN 12. What are the equilibrium quantities and price?

• A54 each; P = MXN 12
• B27 each; P = MXN 66
• C36 each; P = MXN 48
• D48 each; P = MXN 24

In a Bertrand duopoly with a homogeneous product, identical marginal cost of MXN 15 and no capacity limits, what is the Nash equilibrium?

• ABoth charge the joint-monopoly price of MXN 45
• BOne charges MXN 20 and the other MXN 15, taking the whole market
• CBoth randomize prices between MXN 15 and MXN 30
• DBoth charge MXN 15 and earn zero economic profit

Firm 1 leads and Firm 2 follows in a Stackelberg duopoly with linear demand and equal constant costs. How does the outcome compare with Cournot?

• AThe leader produces and earns more; the follower produces and earns less
• BBoth firms produce the same output, but the leader charges a higher price
• CThe leader cuts output below the Cournot level to push up the market price
• DTotal industry output is lower and the price higher than under Cournot

In a 2×2 game, payoffs (Firm 1, Firm 2) are: (Up, Left) = (5, 4); (Up, Right) = (3, 2); (Down, Left) = (4, 1); (Down, Right) = (1, 6). Which statement is correct?

• AFirm 2's dominant strategy is Right; the equilibrium is (Down, Right)
• BUp is strictly dominant for Firm 1; the equilibrium is (Up, Left)
• CNeither firm has a dominant strategy, and there are two equilibria
• DDown is dominant for Firm 1; the equilibrium is (Down, Left)

In matching pennies, Player 1 wins 1 if the coins match and loses 1 if they differ; Player 2 gets the opposite. What is the Nash equilibrium?

• ABoth play Heads with certainty
• BPlayer 1 plays Heads 75% of the time, and Player 2 plays Tails 75%
• CBoth play Heads and Tails with probability 0.5 each
• DThe game has no equilibrium, in pure or mixed strategies

An entrant chooses Enter or Stay Out; after entry, the incumbent chooses Accommodate or Fight. Payoffs (entrant, incumbent): Stay Out (0, 10); Enter-Accommodate (3, 5); Enter-Fight (-2, 1). What is the subgame perfect equilibrium?

• AThe entrant stays out, because the threat to fight is credible
• BThe entrant enters and the incumbent fights
• CThere is none, because information is imperfect
• DThe entrant enters and the incumbent accommodates

In an Edgeworth box with two consumers and two goods, what condition defines the contract curve of interior Pareto-efficient allocations?

• AMRS of consumer A equals MRS of consumer B
• BEach consumer holds exactly half of each good
• CBoth consumers spend the same amount of money
• DBoth consumers' marginal utilities equal zero

What does the First Fundamental Theorem of Welfare Economics state?

• AAny efficient allocation can be reached with markets plus lump-sum transfers
• BUnder its assumptions, every competitive equilibrium is Pareto efficient
• CCompetitive markets guarantee a fair income distribution
• DRegulated monopoly always beats competition at reducing deadweight loss

A chemical plant's private marginal cost is MPC = 20 + 2Q, and the marginal external damage from its pollution is MEC = Q. Demand is P = 140 - Q. What are the market output and the socially optimal output?

• AMarket 30, optimum 40
• BMarket 45, optimum 35
• CMarket 40, optimum 30
• DMarket 50, optimum 25

In the same case (MPC = 20 + 2Q, MEC = Q, demand P = 140 - Q, optimum Q = 30), what per-unit Pigouvian tax achieves the optimum?

• AMXN 10
• BMXN 20
• CMXN 25
• DMXN 30

According to the Coase theorem, when does private bargaining produce an efficient outcome despite an externality?

• AWhen property rights are clear and transaction costs negligible
• BWhen the government sets production quotas on the polluter
• COnly when rights belong to the party harmed by the externality
• DWhen courts order equal compensation through class actions

What is the Samuelson condition for efficient provision of a pure public good with N consumers?

• AEach consumer's MRS equals the MRT separately
• BThe sum of the consumers' MRS equals the MRT
• CThe MRT equals zero, because the good is non-rival
• DThe sum of firms' MRT equals one consumer's MRS

What distinguishes adverse selection from moral hazard?

• AAdverse selection occurs in credit markets; moral hazard occurs only in health insurance
• BAdverse selection is hidden action after contracting; moral hazard is a hidden type before
• CAdverse selection is hidden type before contracting; moral hazard is hidden action after
• DAdverse selection is solved with deductibles, while moral hazard needs nationalization

An economy's national accounts show, in billions of pesos: private consumption 6,200; gross investment 1,900; government purchases 1,500; exports 1,300; imports 1,700. What is GDP by the expenditure approach?

• A10,900
• B9,600
• C10,000
• D9,200

In Year 1 (the base year) an economy sells 100 t of wheat at MXN 20/t and 50 t of steel at MXN 100/t. In Year 2 it sells 120 t of wheat at MXN 25/t and 60 t of steel at MXN 120/t. What are Year 2 nominal GDP, real GDP and the GDP deflator?

• ANominal 10,200; real 8,400; deflator 121.4
• BNominal 8,400; real 10,200; deflator 82.4
• CNominal 10,200; real 7,000; deflator 145.7
• DNominal 7,000; real 8,400; deflator 120.0

What is a key difference between a consumer price index such as the INPC and the GDP deflator?

• AThe CPI uses changing (Paasche) weights, while the deflator uses a fixed Laspeyres basket
• BThe CPI prices a fixed consumer basket with imports; the deflator, all domestic output
• CThe CPI includes capital goods and military purchases, which the deflator leaves out
• DThe CPI corrects fully for substitution bias, while the deflator overstates inflation

A country's current account balance is -35 billion dollars and net errors and omissions are -2 billion dollars. Under a clean float, with no change in official reserves, what is the balance of the capital and financial account?

• A-37 billion
• B-33 billion
• C+37 billion
• D0

The identity (S_private - I) + (T - G) = CA holds. If the fiscal deficit widens while private saving and investment stay the same, what happens to the current account?

• AIt moves into a larger surplus
• BPrivate investment rises to match the deficit
• CPrivate saving rises to offset all of the deficit
• DIts deficit widens by the same amount (twin deficits)

In an input-output table, manufacturing buys MXN 30 billion of agricultural inputs, and manufacturing's gross output is MXN 200 billion. What is the technical coefficient of agriculture in manufacturing, and what does it mean?

• A0.15: manufacturing uses 15 centavos of farm inputs per peso of output
• B0.15: agriculture sells 15% of its output to manufacturing
• C6.67: manufacturing produces 6.67 pesos per peso of farm inputs
• D0.30: manufacturing uses 30 centavos of farm inputs per peso of output

A two-sector economy has the Leontief inverse (I - A)⁻¹ with first column (1.50, 0.67) and second column (0.50, 1.33). If final demand for sector 1 rises by 100, how much must each sector's output rise?

• ASector 1 by 100, sector 2 by 0
• BSector 1 by 120, sector 2 by 40
• CSector 1 by 150, sector 2 by 67
• DSector 1 by 150, sector 2 by 50

Where does Banco de México record remittances sent home by Mexican workers abroad in the balance of payments?

• AIn the financial account, as foreign direct investment
• BIn the current account, as primary income
• CIn the capital account
• DIn the current account, as secondary income

In an INEGI ENOE-style survey, the population aged 15 and over is 100 million, the economically active population (PEA) is 60 million and 58.2 million people are employed. What are the unemployment rate and the participation rate?

• A1.8% and 58.2%
• B3.0% and 60.0%
• C3.1% and 60.0%
• D3.0% and 58.2%

The area between the line of perfect equality and a country's Lorenz curve is 0.20, and the whole triangle under the equality line is 0.50. What is the Gini coefficient?

• A0.20
• B0.60
• C0.40
• D0.80

A closed economy has C = 200 + 0.80(Y - T), I = 300, G = 400 and T = 250. What are equilibrium income and the spending multiplier?

• AY = 3,500; multiplier 5.0
• BY = 4,000; multiplier 4.0
• CY = 4,500; multiplier 5.0
• DY = 3,500; multiplier 1.25

In a closed Keynesian economy, the government raises both purchases and lump-sum taxes by MXN 100 million. What is the change in output?

• AZero, because the tax increase cancels the spending
• B+MXN 100 million
• C+MXN 500 million, with a multiplier of 5
• D-MXN 100 million, because taxes hurt confidence

Why does the IS curve slope downward?

• AHigher interest rates make consumers wealthier and so raise their consumption
• BHigher output raises money demand, which pushes interest rates down
• CA lower rate raises investment, which raises output via the multiplier
• DA lower rate causes capital flight that depresses domestic production