1 Indemonstrating the determinationof anoptimal output of a good inthe presence of the spillover effects that it generates, economists have seemingly been unaware or, if aware, have failed to make explicit that a conclusion of the uniqueness of the optimal position depends upon the assumption of zero welfare (or income) effects and zero budgetary restrictions.1 It may, however, also be possible that some economists, although aware of these welfare and budgetary effects, believe that attention to them would serve only to clutter up the analysis without adding anything of much value to the result of the analysis.
There may be cases where the analysis that determines a unique optimal output is valid. But the welfare effects and budgetary restrictions may not be ignored when we are to consider those spillovers that make a substantial difference to people’s welfare – substantial enough, at any rate, to make the question of whether the cost–benefit criterion is met depend crucially upon which of the conflicting groups is the one entitled to compensation.
In general, wherever the adverse spillover takes the form of a pollutant that cannot be entirely or economically removed by technological means, the residual amount of the pollutant must be costed by recourse to compensatory payments.
Concentrating for the present on this residual amount of pollution that cannot economically be removed by any feasible technology, its pertinent cost can be valued as a compensating variation in either of two alternative ways: as the most that a group B, suffering from the pollutant, is willing to pay for its elimination, or else the smallest sum that this group will accept to bear with it. A com-parison of the cost–benefit calculations from using each of these two alternative
1 This is certainly the case in the well-known article by Coase (1960), and is illustrated by his initial example of cattle straying into neighbouring agricultural land, the optimal position (whether in terms of the number of cattle admissible or the cost of fencing) being uniquely determined by existing market prices.
QUAH: “CHAP20” — 2007/1/25 — 18:58 — PAGE 112 — #2 ways of evaluating the damage can, not surprisingly, result in contradictory outcomes.2
2 Once the reader is familiar with the CV12 and CV21 measures of benefits and losses, his attentionmay be drawnto the differences inthe applicationof these alternative measures. In all normal circumstances – those in which welfare effects are positive, as they will almost certainly be for environmental goods or bads – the least sum a personis willing to accept (to forgo a good or to bear with a bad) will, as stated earlier, exceed the largest sum he is willing to pay (to forgo a bad or to enjoy a good). And the difference between the two is magnified when we bring a budgetary constraint into the picture. For, in the absence of any welfare effects, the most a person is able to pay for a good, or for the avoidance of a bad, no matter how important it is for his well-being, is limited by his budget – by his present and expected future income, his assets and by what he canborrow. To illustrate by anextreme example, if he were compelled to undertake a dangerous mission in which his chances of survival were slight, but from which obligationhe would be freed if he could offer a large enough sum of money to induce some other person to undertake the mis-sion, the largest sum he could scrape together would be finite and limited. The limit might be, say, $2.5 million. Conversely, if he were asked to name the smallest sum he would accept for voluntarily accepting to undertake the mis-sion, we would not be surprised if there was no sum large enough to tempt him to do so.
In general, then, the more important to his well-being the item in question, the greater the difference between the most he would pay for it and the smallest sum he would accept to go without it. And it is this phenomenon, the large magnitude of the difference between these two sums that, as we shall see, presents the economist with a problem. For the choice of using the CV12measure or the CV21measure in evaluating the spillovers can determine whether or not the project is able to meet the cost–benefit criterion.
Bearing in mind that the economic activity involved during, say, the operation of the project that unavoidably damages the interests of group B also produces benefits, else it would not be undertaken.And since these benefits, however valued, are reaped by another group, group A, there is clearly a conflict of interest between
2 The seeming contradiction that is possible in applying the Kaldor–Hicks criterion first revealed by Scitovsky (1941) arises in a different economic context; that of a general equilibrium analysis in which the distributionof the available goods is related to their market prices. (See Appendix 3,‘The alleged contradiction of the Kaldor–Hicks criterion’.) Also, recent empirical studies seem to find a consistent divergence between the willingness to pay and the willingness to accept measure. While there are good reasons for this disparity of measures, it appears that the consensus has been that, if there is a welfare loss (as in the case of environmental damage), the choice measure is that of willingness to accept (compensation demanded), while if a project results in a welfare gain (as in the case of environmental improvements), the choice measure is that of willingness to pay. For more on this literature, see Knetsch and Sinden (1984) and Hanemann (1991).
QUAH: “CHAP20” — 2007/1/25 — 18:58 — PAGE 113 — #3 Compensating for environmental damage 113 the two groups.3Therefore, in illustrating the alternative uses of CV12and CV21, we shall compare the value to each of the two groups of that operationof the project producing the damaging spillover effects.
3 The cost–benefit criterion introduced in Part I of this book, that V > 0, was identified as the Kaldor–Hicks test, sometimes also referred to as a potential Pareto improvement, It may now be more precisely expressed as CV12 > 0. This is properly interpreted as requiring for its fulfilment that everyone in the community could be made better off by a costless distributionof the gains inmoving from state 1 to 2.
Yet, it is no less compelling to employ, instead, the alternative criterion,
CV21 < 0, which is properly interpreted as requiring for its fulfilment that everyone in the community could be made worse off by a costless distributionof the losses that are incurred in moving from state 2 back again to state 1.
Admittedly, a superficial reflectionwould suggest that, if CV12 > 0, then indeed CV21< 0 and vice versa. After all, if it is true that everyone can indeed be made better or worse off by a movement from state 1 to state 2, then the return to state 1 must be able, respectively, to make everyone worse or better off. Yet, it is easy to show that having regard now that in absolute magnitude, CV21can exceed CV12 or vice versa, for each personaffected, this superficial reflection referred to is far from certain.
Granted that the choice of the calculation CV12rather thanthe calculationof the CV21or vice versa canmake a crucial difference, the questionarises: which of these alternative criteria should the economist adopt? On economic grounds alone, there can be no convincing answer.4It follows that if, for any reason, the political decisionmakers were to require the economist to employ the CV12> 0 criterionrather thanthe alternative CV21 < 0 criterion, or the reverse of this, the economist would have no grounds for demurring. He may accept the decision as a valid political constraint.
It is, perhaps, unnecessary to remark that one cannot altogether rule out the possibility that, for every personaffected, CV12 is (ignoring the sign) exactly equal to the magnitude of CV21, inwhich case the CV12calculationis exactly equal (save for the sign) to the CV21calculation and, if the one criterion is met, so will be the other. But once the magnitude of CV12and CV21differs for each person, as they generally would, the magnitude of the CV12 calculationwill differ from that of the CV21and, which is more important, it becomes possible for the CV12> 0 criterionto fail, while the CV21 < 0 criterionto succeed. It also becomes possible for both CV21< 0 an d CV12< 0.
3 It is not impossible that some people will be in both groups; as a gainer from the good being produced by the project and also a loser from the spillover it generates. This possibility, however, in no way makes any difference to the analysis.
4 Any proposal that we use the CV21calculationfor some items and the CV12calculationfor others has to be vetoed, as no clear interpretation could be made of the resulting combined calculation.
QUAH: “CHAP20” — 2007/1/25 — 18:58 — PAGE 114 — #4 4 Bearing in mind the conflict between groupAand group B for operations of the project that generate environmental spillovers, if we suppose that the movement from a state 1 to a state 2, one that also damages the environment, is one that involves group B in a loss, then the movement from state 2 to state 1 that, instead, improves the environment is one that confers a benefit on group B – the opposite being true for group A. Since for each of these four possibilities we can use either the CV12calculationor the CV21calculation, we shall use each case to illustrate a distinct proposition. The four propositions are as follows:
(i) If CV12 > 0, and therefore the project is accepted on that criterion, it necessarily follows that CV21< 0, which confirms the acceptability of the project.
(ii) If CV21 > 0, and therefore on that criterion, the project is rejected, it necessarily follows that CV12 < 0, which confirms the rejection of the project.
(iii) If CV12 < 0, and therefore the project is rejected on that criterion, it is possible that CV21 > 0, so confirming the rejection of the project. But it is also possible that CV21 < 0, so that, onthis latter criterion, the project is accepted, contrary to the CV12criterion.
(iv) If CV21 < 0, and therefore onthat criterionthe project is accepted, again it is possible that CV12 > 0, so confirming the acceptance of the project.
But it is also possible that CV12 < 0 which, onthat criterion, rejects the project, contrary to the acceptance by the CV21criterion.
5 We now use four simple examples that will illustrate the validity of each of these four propositions in the order stated above.
(i) The first example is that of the introduction of a project – the movement from state 1 to state 2 – that eliminates the effluent that hitherto existed in that area, this being a gain to group B while incidentally causing a loss to groupA. Using the CV12measure, we shall suppose that the most that group B would pay to move to state 2, one that eliminates the effluent, is (in million dollars) equal to 100, while the smallest amount acceptable to group A which has to suffer a loss inmoving to state 2 is equal to 80. The CV12of both groups taken together is thenequal to +100, −80 or +20 (bearing in mind our convention of a plus sign for a payment and a minus sign for a receipt). Since CV12> 0, the CV12criterion sanctions the project.
If, instead we employ the CV21 criterion, which addresses itself to the relevant sums for a return from state 2 to the original state 1, group B will lose in now having to put up with the effluent, while group A will gain.
Since the least sum that group B will accept to move back to state 1 must exceed the most it would pay to move to state 2, we may suppose its CV21 to be equal to 110. As for group A, which loses inthe movement to state 2, it gains if the movement is back to the original state 1. But the most it will pay for the returnto state 1 must be less thanthe least sum it required
QUAH: “CHAP20” — 2007/1/25 — 18:58 — PAGE 115 — #5 Compensating for environmental damage 115 inmoving to state 2. It will therefore be less than80; say it is equal to 70. The CV21 of both groups takentogether is thenequal to −110, +70 or −40. Thus the CV21 < 0 criterionis met and, a fortiori the project is accepted. (This example, illustrating proposition (i) is summarized in Table 20.1.)
(ii) Inorder to illustrate the second propositioninwhich CV21 > 0 rejects the project, we shall suppose that the movement from state 1 to state 2 is one that creates effluent so that, if the project is adopted, group B will lose and group A will gain.
Inorder for CV21to be positive, the most that group B is willing to pay for a return to the original (no effluent) state 1, must exceed in magnitude the smallest sum acceptable to group A for this returnto state 1. We may therefore suppose these sums to be +100 for group B and −80 for group A, takentogether equal to +20.
The alternative CV12measure for group B, being the smallest sum accept-able for moving to the effluent state 2, must, however, exceed the most it would pay, 100, to avoid the effluent, say it is 110. As for group A, since it would accept no less than 80 to agree to move back to the non-effluent state 1, it would pay less thanthis to move to the effluent state 2, say 70.
If follows that the total CV12 of the two groups comes to −110, +70 or
−40. Consequently, it transpires that a fortiori CV12 < 0, which confirms the initial rejection of the project by CV21> 0.
This example, which illustrates our second proposition, is summarized in Table 20.2.
6 The two remaining propositions (iii) and (iv) are illustrated in Tables 20.3 and 20.4, respectively, without further explanation, provided the reader bears in mind that the minimum sum acceptable to either group to forgo a good (or to bear with a bad) is always larger thanthe maximum sum it is willing to pay for the good or
Table 20.1
A B (A+B)
CV12 −80 100 20 (project accepted)
CV21 70 −110 −40 (project accepted)
Table 20.2
A B (A+B)
CV21 −80 100 20 (project rejected)
CV12 70 −110 −40 (project rejected)
QUAH: “CHAP20” — 2007/1/25 — 18:58 — PAGE 116 — #6 Table 20.3
A B (A+B)
(a) CV12 100 −120 −20 (project rejected) (b) CV21 −110 115 5 (project rejected) (c) CV21 −130 120 −10 (project accepted)
Table 20.4
A B (A+B)
(a) CV21 −120 100 −20 (project accepted) (b) CV12 110 −105 5 (project accepted) (c) CV12 100 −120 −20 (project rejected)
the removal of the bad. These are the two ambiguous cases, and the ambiguity is revealed ineach case by the fact that, ineach of these tables, use of the identical criterioninrows (b) and (c) canbe shownto confirm and to contradict, respectively, the result of the criterioninrow (a).
It may be noted inpassing that, whenthe project inquestionis one that creates, or increases pollution, the employment of the CV12 > 0 criteriontends to act against adopting the project, as group B has recourse to the larger sum, the minimum acceptable, rather than to the smaller sum, the most it could pay to avoid the pollution. Per contra, when the project is one that improves the environment, the CV12> 0 will tell against group B, because it is the smaller sum, the most it can afford to pay for the improvement, that is to count. In that case, the employment instead of the CV21 < 0 criterionwill act to favour group B, because the sum involved becomes the larger one – the least it would accept for returning to the original state 1 (which existed prior to the removal of the pollution).
7 To be sure, those spillovers, positive or negative, that cannot be uniquely priced by reference to the market, and for which, therefore, we have to resort to evaluating by either CV12or CV21, may be a relatively small component of the total effects produced by the project. Insuch cases, the rejectionor acceptance of the project as a whole by either criterionwill be unaffected by the evaluationof the spillovers in question. But as the spillover component of the project assumes greater proportions, the choice of the CV12 > 0 or the CV21 < 0 canbe the decisive factor inthe acceptance or rejectionof the project.
Consider, for example a proposal to clear 100,000 acres of forest land in order to use the land for agricultural purposes. The benefits over the future would be reckoned as the discounted sum of the annual excess of the value of crops to the consumers less the opportunity costs of producing them for each of the next
QUAH: “CHAP20” — 2007/1/25 — 18:58 — PAGE 117 — #7 Compensating for environmental damage 117 m years. If, however, the farmers were to bid for the land or to be compensated for being denied its use, they would reckon the benefits in terms of expected profits.
Conversely, the loss to the community if such a project were implemented would take into account the irrevocable loss for present and future generations arising from the destruction of a variety of species of flora and fauna and the recreational facilities the forest provides.
Onthe CV21 < 0 criterion that would be used under a ruling or order that requires those who oppose the scheme to recompense those prepared to cultivate the land, producing goods of real value that would augment GNP, it is highly likely that the criterion would be met, and the scheme approved. Yet, as we know from proposition (iv), this result could be contradicted if, instead, we employed the
CV12> 0 criterion, this possible contradiction being that illustrated in row (c) of Table 20.4. For using the CV12> 0 criterion in this instance, the minimal sum demanded by the community to suffer the loss of this vast forest land is almost sure to be far in excess of any sum the farmers could offer. The scheme, then, could not be vindicated by a CBA.
The same argument would, of course, apply to the activities of logging com-panies devoted to cutting down many thousands of acres of tropical woodlands each year. For all practical purposes, the loss to society is irrevocable because, given that such trees generally require hundreds of years to reach their full stature, the re-planting of such trees is hardly an attractive economic proposition. Such activities, it may be concluded with confidence, would never be able to meet the
CV12criterion.
Finally, inorder to illustrate proposition(iii), inparticular the possibility exem-plified by row (c) inTable 20.3, we may suppose that, two decades ago, a small workshop for producing bicycle tyres was established within a residential area currently inhabited by 5,000 families. The enterprise so prospered that the origi-nal small shed gave way to a large factory producing car tyres and housed in an overtowering building, one that was not only an eyesore to the residents, but was also spewing clouds of black smoke from its twin chimneys and creating a foul smell that spread over most of the area.
The residents – desperate to move from the existing pollution state 1 to a non-pollutionstate 2 – offered as much as $200 millionto the factory owner to site his works elsewhere. The latter made it clear, however, that he would require at least
$250 millionto cover the full costs of such re-siting of his works. The CV12> 0 criterion cannot therefore be met, as the CV12 aggregate amounted to −$50 million.
If, now, onappeal to the courts, the property rights inthe ambient air, inand above the residential area, were granted to the residents who, coming together, agreed they would no longer tolerate this blight on their lives unless they received incompensationno less than$500 million– just enough to enable families to move elsewhere – the factory owner would have no choice but to site his works in some
If, now, onappeal to the courts, the property rights inthe ambient air, inand above the residential area, were granted to the residents who, coming together, agreed they would no longer tolerate this blight on their lives unless they received incompensationno less than$500 million– just enough to enable families to move elsewhere – the factory owner would have no choice but to site his works in some