Economía Ayudantía # 03: Externalidades

Transcripción

1 Ayudantía # 03: Externalidades Profesor: Carlos R. Pitta 1 1 cpitta@spm.uach.cl

2 PREGUNTAS BREVES Comente 01: Si Dick Posee un perro cuyos ladridos molestan a su vecina Jane. Suponga que el beneficio de tener el perro vale $500 para Dick y que Jane soporta un costo de $700 por los ladridos. En esta situación, y dada la estructura de las valoraciones personales personales, asumiendo que Dick tiene el derecho legal de quedarse con el perro, no existe una posible solución privada a este problema. RESPUESTA: FALSO. Una posible solución sería, por ejemplo, que Jane le paga a Dick $650 si accede a entregar el perro a un granjero que vive fuera de Santiago. Comente 02: Los beneficios de los impuestos pigovianos para reducir la contaminación han de sopesarse con las pérdidas irrecuperables de eficiencia que provocan RESPUESTA: FALSO. The statement, "The benefits of corrective taxes as a way to reduce pollution have to beweighed against the deadweight losses that these taxes cause," is false. In fact, corrective taxes reduce the inefficiency of pollution by reducing the quantity of the good being produced that has pollution as a by-product. So, corrective taxes reduce deadweight loss; they do not increase it. Comente 03: Suponga que en un mercado existe una externalidad negativa que el gobierno desea corregir. Al tomar la decisión sobre si poner un impuesto correctivo sobre los consumidores o sobre los productores, el gobierno debe ser cuidadoso e imponer el impuesto en el lado del mercado, ya sea la oferta o la demanda, que produce la externalidad. RESPUESTA: FALSO. The statement, "When deciding whether to levy a corrective tax on consumers or producers, the government should be careful to levy the tax on the side of the market generating the externality," is inaccurate. It does not matter on whom the tax is imposed the incidence of the tax will be identical. So whether the externality is caused by the seller or the buyer of a good, a tax on either producers or consumers will lead to the same reduction of quantity and change in the prices producers receive or consumers pay. Pregunta Corta 01: Imagine que usted es una persona que no fuma y comparte una habitación con un fumador. Según el teorema de Coase, de qué depende que su compañero fume o no en la habitación? Es eficiente este resultado? Cómo llegan usted y su compañero a esta solución? RESPUESTA: According to the Coase theorem, you and your roommate will bargain over whether your roommate will smoke in the room. If you value clean air more than your roommate values smoking, the bargaining process will lead to your roommate not smoking. But if your roommate values smoking more than you value clean air, the bargaining process will lead to your roommate smoking. The outcome is efficient as long as transaction costs do not prevent an agreement from taking place. The solution may be reached by one of you paying off the other either not to smoke or for the right to smoke. PROBLEMAS Problema 01: Considere el mercado de extintores de incendios. a) Por qué podrían mostrar los extintores de incendios externalidades positivas en el consumo? b) Represente gráficamente el mercado de extintores, indicando la curva de demanda, la curva de valor social, la curva de oferta y la curva de coste social. c) Indique el nivel de producción de equilibrio del mercado y el nivel eficiente de producción. Explique Intuitivamente por qué son diferentes estas cantidades. d) Si el beneficio externo es de $10 por extintor, describa una política que daría un resultado eficiente. a. Fire extinguishers exhibit positive externalities because even though people buy them for their own use, they may prevent fire from damaging the property of others. b. Figure 2 illustrates the positive externality from fire extinguishers. Notice that the social value curve is above the demand curve and the social cost curve is the same as the supply curve. c. The market equilibrium level of output is denoted Q market and the efficient level of output is denoted Q optimum. The quantities Prof. Carlos R. Pitta 2

3 differ because in deciding to buy fire extinguishers, people don't account for the benefits they provide to other people. d. A government policy that would result in the efficient outcome would be to subsidize people $10 for every fire extinguisher they buy. This would shift the demand curve up to the social value curve, and the market quantity would increase to the optimum quantity. Problema 02: A Ringo le encanta tocar rock and roll a un elevado volumen. A Luciano le encanta la ópera y odia el rock and roll. Desgraciadamente, son vecinos en un edificio de apartamentos que tiene las paredes muy finas. a) Cuál es en este caso la externalidad? b) Qué política de orden y control podría imponer el casero? Podría dar un resultado ineficiente esa política? c) Supongamos que el casero permite a los inquilinos hacer lo que quieran. Según el teorema de Coase, cómo podrían Ringo y Luciano llegar por su cuenta a un resultado eficiente? Qué podría impedírselo? a. The externality is noise pollution. Ringo s consumption of rock and roll music affects Luciano, but Ringo does not consider that in deciding how loud he plays his music. b. The landlord could impose a rule that music could not be played above a certain decibel level. This could be inefficient because there would be no harm done by Ringo playing his music loud if Luciano is not home. c. Ringo and Luciano could negotiate an agreement that might, for example, allow Ringo to play his music loud at certain times of the day. They might not be able to reach an agreement if the transaction costs are high or if bargaining fails because each holds out for a better deal. Problema 03: Si aumenta el consumo de bebidas alcohólicas, aumenta el número de accidentes de tráfico y, por lo tanto, se imponen costes a las personas que no beben ni conducen. a) Muestre el mercado de bebidas alcohólicas, indicando la curva de demanda, la curva de valor social, la curva de oferta, la curva de coste social, el nivel de producción de equilibrio del mercado y el nivel eficiente de producción. b) Sombree en su gráfico el área correspondiente a la pérdida irrecuperable de eficiencia del equilibrio del mercado (pista: la pérdida irrecuperable se produce porque se consumen algunas unidades de alcohol cuyo coste social es superior al valor social). Explique su respuesta. a. The market for alcohol is shown in Figure 3. The social value curve is below the demand curve because of the negative externality from increased motor vehicle accidents caused by those who drink and drive. The free-market equilibrium level of output is Q market and the efficient level of output is Q optimum. b. The triangular area between points A, B, and C represents the deadweight loss of the market equilibrium. This area shows the amount by which social costs exceed social value for the quantity of alcohol consumption beyond the efficient level. Prof. Carlos R. Pitta 3

4 Figure 3 Problema 04: El río Pristino tiene dos empresas contaminantes en sus orillas. Acme Industrial y Productos Químicos Creativos vierten cada una 100 toneladas de residuos al río todos los años. El coste de la reducción de las emisiones de residuos por tonelada es igual a $10 en el caso de Acme y a $100 en el de Productos Químicos. La administración local quiere reducir la contaminación general de 200 toneladas a 50. a) Si la administración supiera cuál es el coste de reducción de cada empresa, qué reducciones impondría con el fin de alcanzar su objetivo general? Cuál sería el coste para cada empresa y el coste total para las dos empresas en conjunto? b) En una situación más representativa, la administración sabría cuál es el coste de la reducción de la contaminación de cada empresa. Si decidiera alcanzar su objetivo general imponiendo Una reducción uniforme a las dos empresas, calcule la reducción que realizaría cada una, el coste de cada empresa y el coste de las dos empresas conjuntamente. c) Compare el coste total de la reducción de la contaminación de las partes (a) y (b). Si la administración no sabe cuál es el coste de reducción de cada empresa, existe aún otra forma de reducir la contaminación a 50 toneladas con el coste total calculado en la parte (a)? Explique su respuesta. a. If the government knew the cost of reduction at each firm, it would have Acme eliminate all its pollution (at a cost of $10 per ton times 100 tons = $1,000) and have Creative eliminate half of its pollution (at a cost of $100 per ton times 50 tons = $5,000). This minimizes the total cost ($6,000) of reducing the remaining pollution to 50 tons. b. If each firm had to reduce pollution to 25 tons (so each had to reduce pollution by 75 tons), the cost to Acme would be 75 x $10 = $750 and the cost to Creative would be 75 x $100 = $7,500. The total cost would be $8,250. c. In Part a, it costs $6,000 to reduce total pollution to 50 tons, but in Part b it costs $8,250. So it is definitely less costly to have Acme reduce all of its pollution and have Creative cut its pollution in half. Even without knowing the costs of pollution reduction, the government could achieve the same result by auctioning off pollution permits that would allow only 50 tons of pollution. This would ensure that Acme reduced its pollution to zero (because Creative would outbid it for the permits) and Creative would then reduce its pollution to 50 tons. Problema 05: Suponga que el gobierno decide emitir permisos transferibles para un determinado tipo de contaminación. a) Es importante para la eficiencia económica que distribuya los permisos o los subaste? Es importante para otros aspectos? b) Si el gobierno decide distribuir los permisos, es importante para la eficiencia su distribución entre las empresas? Y para otros aspectos? a. In terms of economic efficiency in the market for pollution, it does not matter if the government distributes the permits or auctions them off, as long as firms can sell the permits to each other. The only Prof. Carlos R. Pitta 4

5 difference would be that the government could make money if it auctioned the permits off, thus allowing it to reduce taxes, which would help reduce the deadweight loss from taxation. There could also be some deadweight loss occurring if firms use resources to lobby for additional permits. b. If the government allocated the permits to firms who did not value them as highly as other firms, the firms could sell the permits to each other so they would end up in the hands of the firms who value them most highly. Thus, the allocation of permits among firms would not matter for efficiency. But it would affect the distribution of wealth, because those who got the permits and sold them would be better off. Problema 06: Suponga que En Valle Feliz hay tres empresas industriales: EMPRESA NIVEL INICIAL DE CONTAMINACIÓN (UNIDADES) A B C COSTE DE REDUCCIÓN DE LA CONTAMINACIÓN EN 1 UNIDAD (DÓLARES) Las autoridades quieren reducir la contaminación a 120 unidades, por lo que conceden a cada empresa 40 permisos transferibles de contaminación. a) Quién vende permisos y cuántos vende? Quién los compra y cuántos compra? Explique brevemente por qué los vendedores y los compradores están dispuestos cada uno a hacerlo. Cuál es el coste total de la reducción de la contaminación en esta situación? b) Cuánto aumentarían los costes de la reducción de la contaminación si los permisos no pudieran transferirse? a. A permit is worth $25 to firm B, $20 to firm A, and $10 to firm C, because that is the cost of reducing pollution by one unit. Because firm B faces the highest costs of reducing pollution, it will keep its own 40 permits and buy 40 permits from the other firms, so that it can still pollute 80 units. That leaves 40 permits for firms A and C. Because firm A values them most highly, it will keep its own 40 permits. So it must be that firm C sells its 40 permits to firm B. Thus firm B does not reduce its pollution at all, firm A reduces its pollution by 30 units at a cost of $20 x 30 = $600, and firm C reduces its pollution by 50 units at a cost of $10 x 50 = $500. The total cost of pollution reduction is $1,100. b. If the permits could not be traded, then firm A would have to reduce its pollution by 30 units at a cost of $20 x 30 = $600, firm B would reduce its pollution by 40 units at a cost of $25 x 40 = $1,000, and firm C would reduce its pollution by 10 units at a cost of $10 x 10 = $100. The total cost of pollution reduction would be $1,700, $600 higher than in the case in which the permits could be traded. Prof. Carlos R. Pitta 5

6 SECCIÓN DE RESPUESTAS Problema 01: Problema 02: a. Figure 4 shows the market for beer without the tax. The equilibrium price is P 1 and the equilibrium quantity is Q 1. The price paid by consumers is the same as the price received by producers. Figure 4 Figure 5 b. When the tax is imposed, it drives a wedge of $2 between supply and demand, as shown in Figure 5. The price paid by consumers is P 2, while the price received by producers is P 2 $2. The quantity of beer sold declines to Q 2. Problema 03: If the government imposes a $500 tax on luxury cars, the price paid by consumers will rise less than $500, in general. The burden of any tax is shared by both producers and consumers the price paid by consumers rises and the price received by producers falls, with the difference between the two equal to the amount of the tax. The only exceptions would be if the supply curve were perfectly elastic or the demand curve were perfectly inelastic, in which case consumers would bear the full burden of the tax and the price paid by consumers would rise by exactly $500. Problema 04: a. Figure 9 shows the effect of a tax on gun buyers. The tax reduces the demand for guns from D 1 to D 2. The result is a rise in the price buyers pay for guns from P 1 to P 2, and a decline in the quantity of guns from Q 1 to Q 2. Figure 9 b. Figure 10 shows the effect of a tax on gun sellers. The tax reduces the supply of guns from S 1 to S 2. The result is a rise in the price buyers pay for guns from P 1 to P 2, and a decline in the quantity of guns from Q 1 to Q 2. Prof. Carlos R. Pitta 6

7 Figure 10 c. Figure 11 shows the effect of a binding price floor on guns. The increase in price from P 1 to P f leads to a decline in the quantity of guns from Q 1 to Q 2. There is excess supply in the market for guns, because the quantity supplied (Q 3 ) exceeds the quantity demanded (Q 2 ) at the price P f. Figure 11 d. Figure 12 shows the effect of a tax on ammunition. The tax on ammunition reduces the demand for guns from D 1 to D 2, because ammunition and guns are complements. The result is a decline in the price of guns from P 1 to P 2, and a decline in the quantity of guns from Q 1 to Q 2. Figure 12 Problema 05: a. The effect of a $0.50 per cone subsidy is to shift the demand curve up by $0.50 at each quantity, because at each quantity a consumer's willingness to pay is $0.50 higher. The effects of such a subsidy are shown in Figure 14. Before the subsidy, the price is P 1. After the subsidy, the price received by sellers is P S and the effective price paid by consumers is P D, which equals P S minus $0.50. Before the subsidy, the quantity of cones sold is Q 1 ; after the subsidy the quantity increases to Q 2. Prof. Carlos R. Pitta 7

8 Figure 14 b. Because of the subsidy, consumers are better off, because they consume more at a lower price. Producers are also better off, because they sell more at a higher price. The government loses, because it has to pay for the subsidy. Problema 06: a. Bert s demand schedule is: Price Quantity Demanded More than $7 0 $5 to $7 1 $3 to $5 2 $1 to $3 3 $1 or less 4 Bert s demand curve is shown in Figure 9. Figure 9 b. When the price of a bottle of water is $4, Bert buys two bottles of water. His consumer surplus is shown as area A in the figure. He values his first bottle of water at $7, but pays only $4 for it, so has consumer surplus of $3. He values his second bottle of water at $5, but pays only $4 for it, so has consumer surplus of $1. Thus Bert s total consumer surplus is $3 + $1 = $4, which is the area of A in the figure. c. When the price of a bottle of water falls from $4 to $2, Bert buys three bottles of water, an increase of one. His consumer surplus consists of both areas A and B in the figure, an increase in the amount of area B. He gets consumer surplus of $5 from the first bottle ($7 value minus $2 price), $3 from the second bottle ($5 value minus $2 price), and $1 from the third bottle ($3 value minus $2 price), for a total consumer surplus of $9. Thus consumer surplus rises by $5 (which is the size of area B) when the price of a bottle of water falls from $4 to $2. Problema 07: a. Ernie s supply schedule for water is: Price Quantity Supplied More than $7 4 $5 to $7 3 Prof. Carlos R. Pitta 8

9 $3 to $5 2 $1 to $3 1 Less than $1 0 Ernie s supply curve is shown in Figure 10. Figure 10 b. When the price of a bottle of water is $4, Ernie sells two bottles of water. His producer surplus is shown as area A in the figure. He receives $4 for his first bottle of water, but it costs only $1 to produce, so Ernie has producer surplus of $3. He also receives $4 for his second bottle of water, which costs $3 to produce, so he has producer surplus of $1. Thus Ernie s total producer surplus is $3 + $1 = $4, which is the area of A in the figure. c. When the price of a bottle of water rises from $4 to $6, Ernie sells three bottles of water, an increase of one. His producer surplus consists of both areas A and B in the figure, an increase by the amount of area B. He gets producer surplus of $5 from the first bottle ($6 price minus $1 cost), $3 from the second bottle ($6 price minus $3 cost), and $1 from the third bottle ($6 price minus $5 price), for a total producer surplus of $9. Thus producer surplus rises by $5 (which is the size of area B) when the price of a bottle of water rises from $4 to $6. Problema 08: a. From Ernie s supply schedule and Bert s demand schedule, the quantity demanded and supplied are: Price Quantity Supplied Quantity Demanded $2 1 3 $4 2 2 $6 3 1 Only a price of $4 brings supply and demand into equilibrium, with an equilibrium quantity of two. b. At a price of $4, consumer surplus is $4 and producer surplus is $4, as shown in Problems 3 and 4 above. Total surplus is $4 + $4 = $8. c. If Ernie produced one less bottle, his producer surplus would decline to $3, as shown in Problem 4 above. If Bert consumed one less bottle, his consumer surplus would decline to $3, as shown in Problem 3 above. So total surplus would decline to $3 + $3 = $6. d. If Ernie produced one additional bottle of water, his cost would be $5, but the price is only $4, so his producer surplus would decline by $1. If Bert consumed one additional bottle of water, his value would be $3, but the price is $4, so his consumer surplus would decline by $1. So total surplus declines by $1 + $1 = $2. Prof. Carlos R. Pitta 9