环境管理_环境经济学培训资料

Fundamentals of Environmental Economics,Weiqi CHEN （陈伟琪）,Environmental Science Research Center Xiamen University,Chapter 3 Benefits and Costs, Supply and Demand Chapter 4 Economic Efficiency and Markets Chapter 5 The Economics of Environmental Quality,SECTION 2: ANALYTICAL TOOLS,This section covers some of the basic ideas of economics and of their application to environmental matters. the purpose : to develop a set of “analytical tools“ - use to focus on issues of environmental quality,Chapter 3 Benefits and Costs, Supply and Demand In this chapter we cover certain basic tools of microeconomics - use in analyzing environmental impacts and policies A key aspect of an economic approach to decision making is the evaluation of the benefits and costs of any action.,economic actions, including environmental actions - have two sides: create value encounter costs evaluate / trade-offs,WILLINGNESS TO PAY Demand AGGREGATE DEMAND/WILLINGNESS TO PAY BENEFITS COST Opportunity Cost Cost Curves The Shapes of Cost Curves TECHNOLOGY THE EQUIMARGINAL PRINCIPLE MARGINAL COST AND SUPPLY,WILLINGNESS TO PAY,The value side of our analysis is based on the fundamental notion: - individuals have preferences for goods and services; given a choice they can express preferences for one good over another, or one bundle of goods over another bundle,The value of a good to somebody is what he is willing to pay for it. how much a person is willing to pay to obtain some good or service, or some environmental asset - its partly a question of individual values,examples,the Canadian Rockies,sacrifice a lot,a quiet living environment,the habitat of unique animal species,the habitat of unique plant species,Golden gate bridge,a persons wealth affects their willingness to sacrifice; the more wealthy a person is, the better they can afford to pay for various goods and services. Willingness to pay, in other words, also reflects ability to pay.,Lets consider the willingness to pay of a person for a particular good. Assume that the person has none of the good to begin with. ask or perhaps deduce from watching her spend her money - how much she would be willing to pay for a single unit of a good rather than go without Fig.1 The Concept of Willingness to Pay,WILLINGNESS TO PAY,38,26,17,12,$,Units of the Good, ,people can consume fractions of items in addition to integer values -a smoothly shaped willingness-to-pay curve,These numbers depict a fundamental relationship of economics: the notion of diminishing willingness to pay. As the number of units consumed increases, the willingness to pay for additional units of that good normally goes down. ,Exceptional circumstances,stamp,submachine gun,drug addict,reputed commodity,Marginal（边际）is thus a word that describes the additional willingness to pay of a person for one more unit. we need to make a distinction between total and marginal,If the person has two units of the good, he want to pay $17 for a third unit - the marginal willingness to pay for the third unit,the total willingness to pay for a given consumption level at a level of three units- the total willingness to pay is $8l ( $38 for the first + $26 for the second + $l7 for the third ) a+b,Demand There is another way of looking at these marginal willingness-to-pay relationships. - demand curves An individual demand curve shows the quantity of a good or service that the individual in question would demand at any particular price. 需求即有支付能力的需要,marginal willingness to pay / demand curve For example, suppose a person whose marginal willingness to pay / demand curve is shown in bottom part of Figure l is able to purchase this item at a unit price of $l7. The quantity he would demand at this price is three units.,An individuals demand / marginal willingness-to-pay curve for a good or service is a way of summarizing their personal consumption attitudes and capabilities for that good.,tastes preferences Incomes Fig.2 Typical Demand / Marginal Willingness-to-Pay Curves,tastes / preferences depend on a lot of factors : psychological and historical factors experiences information,Fig.2 (b)-the same consumers demand curve for a good before / after outdoor wilderness experiences a food item after / before an announcement of the presence in it of pesticide residues,Fig. 2 (b): - The different consumers demand curve for a good - the same consumers demand curve for two different goods,demand curves - curvilinear lines rather than straight lines A straight-line demand relationship would imply a uniform change in the quantity demanded as its price changes. For most goods, however, this is unlikely to be true.,water at low prices and high rates of consumption; at high prices and low quantity demanded a demand relationship - convex to the origin- relatively flat at low prices and steep at higher prices,Individual demand curves indeed summarize the attitudes of single individuals individuals make decisions with only themselves in mind ? Some people may indeed act this way.,But for most there are many other powerful motives that affect their demands for different goods, including altruism toward friends and relatives, feelings of civic virtue toward their communities, a sense of social responsibility toward fellow citizens, and so on. Individual tastes and preferences spring from these factors as well as from more narrow considerations of personal likes and dislikes.,AGGREGATE DEMAND/ WILLINGNESS TO PAY When we examine real-world issues of environmental quality and pollution-control policy, we normally focus our attention on the behaviour of groups of people rather than single individuals. Our interest is in the total, or aggregate, demand / marginal willingness to pay of defined groups of people.,An aggregate demand curve is the summation of a number of individual demand curves. What individuals are involved depends on which particular aggregation we want to look at. the demand of people living in Xiamen for clean water from Jiulong river the demand by people living in the county for public park,The way in which these individual demand curves are summed up depends upon whether the good in question is a private or a public good. Fig. 3 Aggregate Demand / Marginal Willingness-to-Pay Curve - a very simple curve for a private good - the “group“ consists of only three people (A, B, C),summing these individual demand curves horizontally Person A: at l0 units -MWTP $8 Person B: at 6 units -MWTP $8 Person C: at 8 units -MWTP $8 On the aggregate level (24 units), the marginal willingness to pay is also $8.,BENEFITS,The word “benefits“ clearly implies being made better off; if someone is benefited by something, their position is improved, they are made better off. Conversely, if they are made worse off, it must be because benefits were somehow taken away from them.,The benefits that people get from something are equal to the amount they are willing to pay for that thing. It means we can use ordinary demand curves to determine the benefits of making various things available to people.,two aggregate demand curves - the two groups of people to estimate the total benefits from quantity ql to quantity q2 areas under the demand curves between quantity ql and quantity q2 area b / total area a + b ,The people with the higher demand curve must place a greater value on this item - they are willing to pay more than the people whose demand curve is the lower function degradation of the natural environment the impacts of environmental programs and policies a clear notion of the value that people place on different things,recognize shortcomings For one thing demand, and therefore benefits are often very hard to measure when it concerns environmental questions. Demand curves are critically affected by the ability to pay for something as well as preferences. ,The lower demand curve could represent a group of people with lower incomes than those with the higher demand curve. lead us to conclude that the increase in quantity of q2 ql would produce benefits that the lower income people value less than the higher income people. While the logic of the concept is clear, we have to be careful in using it, especially when we are dealing with groups of people with diverse income levels.,An individuals demand for something is clearly affected by how much he knows about it. A person would not be willing to pay for a good if he was ignorant of its very existence. We dont fully understand many of the impacts that environmental degradation is having; furthermore, peoples views about the importance of many of these impacts vary due to influences by the media, the scientific press, and so on., in some of these cases: people are influenced by all kinds of real and imagined factors be cautious about taking peoples demand curves of the moment, as true expressions of the benefits of environmental actions,COST - the other side Any production process requires a variety of productive inputs labour, machinery of various descriptions, energy, raw materials, waste handling equipment, and so on. Valuation of these inputs is straight forward for a private firm operating in a market economy: they are valued according to what they cost to procure in the markets for these items.,a broader concept - opportunity cost Productive inputs used to produce a particular good could have been used to produce a variety of other goods and services. The opportunity cost of producing something consists of the maximum value of other outputs we could and would have produced had we not used the resources to produce the item in question.,People who volunteer their time to clean up trash in parks or on roadsides production residuals are pumped into water environment - affect environmental quality,Opportunity costs are relevant in any situation where a decision must be made about using productive resources for one purpose rather than another.,For a public agency with a given budget, the opportunity costs of a particular policy are the value of alternative policies they may have pursued. For a consumer, the opportunity cost of spending time searching for a particular item is the value of the next most valuable thing to which they may have devoted their time.,Cost Curves Cost information can be summarized with cost curves, which are geometric representations of production costs. differentiate between marginal costs and total costs,Fig. 5 The Concept of Marginal Cost with quantity on the horizontal axis and a monetary index on the vertical axis The cost curves are meant to apply to a single producing organization, a firm, or perhaps a public agency, that is producing some good or service., The top panel shows marginal costs in terms of a stepped-shaped relationship. The bottom panel gives us a smooth marginal cost curve.,marginal cost curves - to determine total production costs the total cost of producing five units : $5+$7+$l0+$l5+$23=$60 The total cost of producing 4.5 units of output is thus given by the area marked a.,The Shapes of Cost Curves The height and shape of the marginal cost curve for any production process will differ from one situation to another. key determining factors technology utilized in production the price of inputs time ( specifically the amount of time that a firm has to adjust to changes in its rate of output ),In general, if input prices increase to a firm or group of firms, this will have the effect of shifting their marginal cost curves upward. a typical short run marginal cost curve for an individual firm - initially declines as output increases but then eventually increases as output gets larger,FIGURE 6 Typical Marginal Cost Curve,Suppose the “output“ refers to the quantity of wastewater handled in a municipal treatment plant. At very low levels of output the plant is not being fully utilized, thus output increases in this range are accompanied by less than proportionate increases in production cost, given marginal costs that diminish. But as output-increases, the capacity of the plant is approached. Machinery must be worked longer, additional people must be hired, etc. Thus, marginal cost begins to increase.,As the capacity of the operation is neared, these problems become more acute. To continue to increase output, more extraordinary measures are required, which can only be done at a high cost, thus, marginal cost increases even more. There may come a point where it becomes almost impossible to increase output further, which is the same as saying that the marginal costs of production at this point increase without limit.,an important generic characteristic of all marginal cost curves - although they may initially decline, they will always increase, eventually, as output becomes large enough. these increases are related to certain underlying factors : increased plant utilization raw materials higher management costs,Will the marginal costs of the larger wastewater treatment plant typically be higher or lower than those of the smaller plant at high output levels?,TECHNOLOGY The most important factor affecting the shapes of marginal cost functions is the technology of the production process. Technology - inherent productive capabilities of the methods and machines being employed,Any modern production requires capital goods (machinery and equipment) of various types and capacities, labour inputs, operating procedures, raw materials, and so on. The quantity of output a firm can get from a given set of inputs depends on the technical and human capabilities inherent in these inputs.,Even within the same industry, marginal cost curves can differ among firms. some older firms with older equipment firms of the same age - different production techniques past managerial decisions,In our simple cost model, technical advancement has the effect of shifting marginal cost curves downward. Technological progress makes it possible to produce a given increase in output at a lower marginal cost. It also reduces total production cost.,Fig.7 Technological Improvement,Technological change normally requires research and development (R&D). R&D in environmental industries is an important activity. the incentive to do R&D is the cost savings ,THE EQUIMARGINAL PRINCIPLE a simple but important economic principle - the “equimarginal“ principle,a single power company - two different generating plants - the same item - the total output of the firm is the sum of what it produces in the two plants the plants were built at different times and make use of different technology the old plant - “A“ the new plant - “B“,Fig.8 The Equimarginal Principle,Consider now a situation where this two-plant firm wants to produce a total output of l00 units. How many units should it produce in each plant, in order to produce the l00 units at the least total cost?,produce 50 units in each plant: total production costs = (a + b + c) + (d) When the output in Plant A is 38 units and the output in Plant B is 62 units, total costs = a + (d + e). the total costs of producing the l00 units in the two plants will be at a minimum only when the marginal costs of the two plants are equal - hence the “equimarginal principle“,If you have multiple sources to produce a given product or achieve a given goal, and you want to minimize the total cost of producing a given quantity of that output, distribute production in such a way as to equalize the marginal costs between the production sources.,If you have a given amount of resources, and you want to maximize the total amount produced, distribute total production among the sources in such a way as to equalize marginal costs. This principle will be very valuable when we take up the issue of getting maximum emissions reductions from given amounts of resources.,MARGINAL COST AND SUPPLY whether private profit-seeking firms (as well as public, politically minded agencies) will produce the correct quantities of output from the standpoint of society in total, for conventional goods and services and the amount of environmental quality. how firms normally determine the quantities they will produce,The marginal cost of production is a key factor in determining the supply behaviour of firms in competitive circumstances. In fact, the marginal cost curve of a firm is its supply curve, showing the quantity of the good the firm would supply at different prices, assuming it can stay in business.,FIG. 9 Marginal Cost and Supply,Assume that the firm is able to sell its output at a price of p*. The firm will maximize its profits by producing that quantity of output where m