A study on the valuing of biodiversity: the case of three endangered species in Brazil
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Transcript of A study on the valuing of biodiversity: the case of three endangered species in Brazil
METHODS
A study on the valuing of biodiversity: the case of threeendangered species in Brazil
Mario Jorge Cardoso de Mendonca a,*, Adolfo Sachsida b,Paulo R.A. Loureiro b
a Instituto de Pesquisa Economica Aplicada (IPEA), Avenida Presidente Antonio Carlos 51, r.1501, Centro, Rio de Janeiro, RJ 20020-
010, Brazilb Universidade Catolica de Brasılia, SGAN 916-Modulo B-Asa Norte, Brasılia, Brazil
Received 17 September 2002; received in revised form 28 February 2003; accepted 17 March 2003
Abstract
Using the analysis developed by Montgomery et al. (J. Environ. Econ. Manage., 1999) as a starting point, this study
establishes the bounds limits to the management price for the conservation of biodiversity. This means, how much the
household would be willing to pay to finance a conservation program for three endangered species in Brazil. This
program must be restricted to the change in habitat with regard to public benefits associated with biodiversity. Here,
this increment in habitat means the marginal benefit derived from the increase in the size of the population. An
important point of this paper is that we work with the robust instrument called the Population Viability Analysis (PVA)
that estimates the survival probability of the species in the future given a current exogenous disturbance. We show that
the results are very sensitive to the parameters of the model, mainly the population’s current size and the degree of
diversity. We also show that the total amount spent on conservation in Brazil is below the socially optimal level,
considering only the three species analyzed in this study.
# 2003 Elsevier Science B.V. All rights reserved.
Keywords: Biodiversity; Management price; Willingness to pay; Population viability analysis
JEL classification: H53; D61
1. Introduction
The value of conserving biodiversity is a recur-
ring issue in environmental economics. However,
what is supposedly being conserved, and what the
relevant trade-off is, are aspects that are not
always clear. The lack of a robust framework
that considers the theoretical and operational
aspects of conservation still plagues biodiversity
valuation. If biodiversity cannot be measured,
then there is no way to make rational decisions
as to what needs to be preserved. In spite of the
fact that the valuing of biodiversity would be
* Corresponding author. Tel.: �/55-21-2240-1920; fax: �/55-
21-3804-8059.
E-mail address: [email protected] (M.J. Cardoso de
Mendonca).
Ecological Economics 46 (2003) 9�/18
www.elsevier.com/locate/ecolecon
0921-8009/03/$ - see front matter # 2003 Elsevier Science B.V. All rights reserved.
doi:10.1016/S0921-8009(03)00080-6
considered as a stage prior to its measuring, thereis an overriding need for the valuing of said
resource, since a proper analysis of ecological
conservation measures would be hindered if this
were not done, considering that each of these bears
the expected gains and immediate losses for the
well-being of society.
With regard to the utility of biodiversity, as
pointed out by Loomis and White (1996), gains areobtained from several types of benefits, and may
be grouped into the following categories. There are
gains that are obtained from the simple pleasure of
being able to observe a certain species. It is
sometimes said that a certain species must be
preserved because of its beauty, or for having a
certain physical characteristic that makes it unique
in a given habitat. These are derived from its valueof use. There are also those produced by the
probable use of genetic information by the phar-
maceutical industry when developing new pro-
ducts. The pharmaceutical industry has been able
to synthesize chemical substances that are impor-
tant for medicine from the study of components
related to the genetics of certain species (DiMasi et
al., 1991). The value of existence is related to thesatisfaction derived simply from knowing that the
preservation of a species is assured in a sustainable
manner. Lastly, we could mention the inheritance
that will be left for future generations.
Starting from the model appearing in Mon-
tgomery et al. (1999), the aim of this paper is to
determine the management price for the preserva-
tion of three endangered Brazilian species. It mustbe kept in mind that this measure does not
represent the value of biodiversity itself, consider-
ing all the aspects that are inherent in such an
issue, but only the value that must be paid by
household in order to bring about a marginal
change in habitat required to increase the survival
capacity of a species. In this study, this change is
characterized by a change in habitat that producesa variation in the current size of the population.
In a market economy, the main goal in deter-
mining a price for any good is the incorporation of
relevant economic information by decision makers
regarding relative values of inputs and outputs.
The analysis developed by Montgomery et al.
(1999), demonstrates how the ‘management price’
may be used to summarize information regardingbiodiversity through the sequence of relations that
connect land use to biodiversity. These involve
relations between the characteristics of the habi-
tats and the individual species’ populations, the
species and its probability of survival, this prob-
ability and the benefits associated with the biolo-
gical diversity and lastly, the benefits and value
they have for society.Basically, this study attempts to establish the
upper and lower limits for the value that society
would be willing to pay, by way of a ‘lump sum’
tax, to support a preservation program for certain
species. It must be pointed out that there are many
issues that need to be addressed here. The pro-
gram’s feasibility or degree of success, the level of
diversity, and the value of use of each species aresome of the factors the play a role in the forming
of prices for species.
This research paper is divided as follows. In
Section 2, a biodiversity pricing model is outlined
in general terms, and at the end of the section we
indicate information that is required so that said
methodology may be applied empirically. In Sec-
tion 3, we further develop the analysis presented inthe previous section, with the aim of finding a way
in which the several concepts comprising the
model may be dealt with empirically. In the
following section, a case study for three Brazilian
endangered species is outlined, based on the
methodology developed in the previous sections.
Lastly, in Section 5, the main conclusions of this
paper are presented.
2. Theoretical model for the valuing of biodiversity
The consumption efficiency for two goods
requires a marginal rate of substitution, defined
as the ratio of the two marginal utilities of said
goods, which is equal to the price ratio. Assuming
that given a certain natural habitat, the utility ofthe agent is derived from two goods, E (D ) and Y ,
where E (D ) is the expected value for biodiversity,
and Y is the aggregate for the other types of
services that may be obtained from said habitat.
Thus, we have that the utility function of the agent
is defined as U�/U (E (D ), Y ). Related to this we
M.J. Cardoso de Mendonca et al. / Ecological Economics 46 (2003) 9�/1810
have PM and PY as the management prices for thepreservation of biodiversity and the price of
aggregate good. The management price, PM ,
represents the value of the contribution of a
change in habitat with regard to public benefits
associated with biodiversity. Here, this increment
in habitat means the marginal benefit derived from
the increase in the size of the population, Xs , for
species s , that equates the marginal rate ofsubstitution between the habitat to its other uses,
X , for said habitat. Thus, by the efficiency
condition we have that
PM �PY
@U=@E(D)
@U=@Y
@E(D)
@Xs
(1)
where D represents a biological diversity index.
The second term on the right side of Eq. (1)represents the rate of substitution between the
expected value of biodiversity and the other uses of
the habitat, while the third term represents the
variation of said expected value given a marginal
increase in the size of the population of species s .
We may affirm that a high value for PM indicates
a high preservation return.
Regarding biodiversity, due to the great dispar-ity in the benefits associated to biodiversity and
those coming from other sources, the application
of this rule becomes complicated. The utility of
biological diversity is due to several factors such as
the maintenance of the integrity of an ecological
system, esthetic distinctions, the option of the
future discovery of a product, etc. Therefore,
when biodiversity is regarded from an economicstandpoint, it must be defined with regard to these
benefits. Thus, the preservation price must repre-
sent the value of the contribution of the benefits
coming from biodiversity produced by an altera-
tion in the habitat for a single land unit.
The biodiversity index, D , is an aggregate
function of a binary variable vector, Z , whose
elements, zis , are equal to one when species s ispresent, or zero when said species is extinct. With
regard to E (D ), this depends on the probability of
survival of said species. This may be obtained from
a concept known as the Shaffer viability (Shaffer,
1983). The viability, V , for a given species s , is the
probability that the size of its population, N , at the
end of some future period T , will surpass a criticallevel NT called the ‘minimum viable population’
(Soule, 1987). This represents the probability of
survival of the species. Hence, we have that:
Vs(Xs;t�0)�Prob(zs�1)
�Prob(Ns;t�T �NT ): (2)
Using the viability concept, the expected value
for the diversity index may be obtained as follows:
E(D)�X2s
i�1
D(Zi)
�YS
s�1
[zisVs(Xs)�(1�zis)(1�Vs(Xs))]; (3)
where i is the index of the possible combinations
for the vectors of Z . The term within the product
is equal to Vs (Xs) when zis �/1 and 1�/Vs(Xs )
when zis �/ 0. With the help of some common
algebraic calculations it may be shown that
PM �PT E(DDs)@Vs(Xs)
@Xs
(4)
where PT is the first term that appears on the right
side of Eq. (1), therefore, PM �PT
@U=@E(D)
@U=@Xo
:
Regarding PT , we may affirm that this term
denotes the value of biodiversity. Eq. (4) then
suggests that four types of information are re-
quired in order to determine the price of diversity:
the set of endemic species and the current state of
each member, the viability function for each
species, a biodiversity index that measures the
contribution of each species in set Z of this index,and lastly, a proxy for the marginal rate of
substitution between biodiversity and the other
benefits obtained from said habitat. In the follow-
ing section, we will show how each one of these
elements may be made explicit.
3. An empirical approach to biodiversity
The objective of this section is the operational
treatment of each component of Eq. (4). We
propose that each of these be analyzed individu-
M.J. Cardoso de Mendonca et al. / Ecological Economics 46 (2003) 9�/18 11
ally, as follows. However, before this is done, it isnecessary to establish appropriate definitions with
regard to the species set, S , object of this analysis,
as well as consider its current state, Xs .
According to internationally recognized criteria
for a survival diagnosis of the species (SSD)
(Master, 1991), the risk of extinction is rated as
follows: 1�/critically endangered species; 2�/en-
dangered species; 3�/vulnerable species; 4�/abun-dant species; although endangered in the long run;
and 5�/the species is safe, given current condi-
tions. The definition of each of these depends on
several factors, such as the estimated number of
elements, threats, fragility, population growth
trends, quality of the habitat, etc. For example,
in a study appearing in Montgomery et al. (1999)
conducted for a set of 147 species of birds, apopulation of less than 50 has a SSD rate of 1;
between 50 and 250, the SSF is 2; between 250 and
1000, the SSD is 3; and for a population over 1000,
the SSD was either four or five.
Regarding viability, a biological preservation
technique called a Population Viability Analysis
(PVA) is commonly used (Lamberson et al., 1992).
It is quite sophisticated, and with it, it is possibleto obtain quantitative estimates regarding the
probability of extinction over a period of time in
the future, say, the next 100 years. These estimates
are based on modeling, and in order to ensure
reliability, since extinction is an extremely complex
and probabilistic phenomenon, they require an
immense quantity of detailed demographic and
genetic data on the species (or population) beingstudied, such as survival and reproduction rates at
different ages, age of the first reproduction, sex
ratio, maximum life span, etc. (Brito and Ferna-
dez, 2000b). Since there are several parameters in
the PVA, we can simulate several interesting
situations by changing these parameters. Thus, if
we want to observe the impact on the probability
of the future condition of a species resulting, forexample, from a substantial reduction in the
number of individuals of the species, this may be
done by altering the parameter regarding the
initial size of the population.
In Brazil, PVA studies are only available for a
very few number of species. In the US and
Australia, estimates are available for hundreds of
species. In Brazil, however, studies adopting thePVA method have been conducted for three
species; the mico-leao-dourado (golden lion ta-
marin), the mico-leao-preto (black lion tamarin),
and a type of cuıca , called Micoureus demerarae.
Some studies have obtained an approximate
estimate based on a logistic viability function.
The reason for this is that the logistical form may
detect the evolution of many biological phenom-ena reasonably well (Bevers et al., 1995).
Let us now take a look at how the literature
deals with the biodiversity measurement issue.
When a species becomes extinct there is a loss in
diversity. This loss may be total, in those cases in
which the family of the species has only one
member, or partial, when the family of said species
also includes other species, as is frequently the casewith birds. Intuitively, it is easy to perceive that the
greatest risk of diversity loss is when the extinct
species does not have a strong relationship with
the surviving members of another related species,
as opposed to those cases in which the extinct
species has a high degree of kinship with the living
related species. The challenge then lies in utilizing
this rationale in a practical manner.A plausible measurement of biological diversity
appears in Krajewsky (1989) and was elaborated
by measuring the genetic distance between any
pair of species for a given set of species. Based on
this methodology, Weitzman (1993) constructs
diversity indexes that present desirable economic
properties. We must keep in mind, however, that
the information required for these indexes is costlyand is not always available.
Some researchers use simpler biodiversity mea-
surements that may be obtained from readily
available information, as is the case of Montgom-
ery et al. (1999). This study presents a biodiversity
measurement based on an index proposed by
Vane-Wright et al. (1991), in which weights for
biodiversity are calculated based on taxonomy.The taxonomy system is constructed according to
perceived similarities among species, and though
far from being perfect, it may be considered a good
substitute indicator for the degree of biodiversity.
In order to construct the weights for each species,
it is only necessary to compute the number of
species that are grouped on each level of classifica-
M.J. Cardoso de Mendonca et al. / Ecological Economics 46 (2003) 9�/1812
tion (order, family, genus, species) and perform thesums down the taxonomic tree for the species. The
weight for species ws is the inverse of this sum
normalized for the one presenting the highest
value (Montgomery et al., 1999). Hence, the
expected value for biodiversity may be expressed
simply as
E(D)�XS
s�1
wsVs(Xs): (5)
Another way of determining the viability values
may be obtained from the classified SSD values. In
this case, extinction probabilities are arbitrarily
attributed according to the degree of SSD. For
example, if a species is rated SSD�/1, then its
viability is Vs(Xs)�/0.1 or Vs (SSDs �/1)�/0.1. If
SSD�/2, then Vs(Xs )�/0.3 or Vs(SSDs �/ 2)�/0.3;and so forth. The increment in viability may be
obtained from the difference in the respective
values of this function. For example, if the
objective of a certain preservation program is to
ensure that a species is out of danger, then DVs �/
Vs(SSDs �/4)�/Vs(SSDs �/1).
Once we have explained how it is possible to
empirically deal with the concepts of biologicaldiversity and viability, we now have to find a way
of translating the first term of Eq. (4), PT , into
numbers, which designates the value of the mar-
ginal substitution rate between the expected diver-
sity and an alternative use of the habitat. This term
PT is the value of diversity. Let us now see how it
is possible to obtain this measurement.
In the attempt to find a way to translate this intomonetary terms, we use the values obtained for
households’ willingness to pay (WTP), meaning
how much these would be willing to pay for the
protection of a specific species in particular loca-
tion. These values can be obtained through a
hypothetical market method called the Contingent
Valuation Method (CVM) that uses a survey to
measure household WTP. A CVM survey isgenerally a referendum in which individuals or
households reveal their WTP for the protection of
a species.
According to Loomis and White (1996), the
upper and lower value limits for WTP are between
US$ 6.91 and US$ 109.451 per year per household
(family), based on WTP studies conducted for 18
endangered species in the US economy. Based on
this, at a discount rate of 10% per year,2 these
values, when considered as ‘lump sum’ disburse-
ments, are respectively US$ 69 and US$ 1.090.
There seems to a certain level of controversy as to
whether the species WTP values obtained by
Loomis and White (1996) may be used as a
numerical base for the value of species PT.
Although most contingent valuation studies at-
tempt to determine values for biodiversity from
specific preservation programs, we must keep in
mind that questions regarding certain aspects of
the species are included in referendums, as well as
other issues (Mitchell and Carson, 1989). Some of
these issues are the desired size of a population,
genus, how payments will be made, etc. What must
remain clear, however, is that population variation
is only one of several factors that determine the
WTP value. Therefore, WTP may thus be used as a
reasonable approximation for the diversity value,
PT . Montgomery et al. (1999) point in the same
direction, in spite of recognizing the limitation of
these values as representative of PT .
In order to value the species considered in this
study, WTP values must be available for a given
species, which is not the case for Brazil. This is due
to the fact that this type of information can only
obtained at a high cost, since a field study,
supported by a contingent valuing method, would
have to be conducted in order to calculate the
WTP. Given the dimensions and high cost, this
should be considered research in its own right, and
is therefore outside the scope of this study.
Although several natural resource valuation stu-
dies have been conducted in Brazil, they cover
issues different than those dealing with the valua-
tion of endangered species, such as deforestation,
CO2 emissions, agricultural losses, etc. (May et al.,
2000).
Since our goal is to introduce a measurement
that may be used as an illustration, this study will
adopt what is known in the literature as the
1 The monetary values appearing in this study were updated
for 1999 US$.2 This rate is commonly used by Brazilian planning institutes.
M.J. Cardoso de Mendonca et al. / Ecological Economics 46 (2003) 9�/18 13
benefits transfer function (Markandya, 1998). Thisfunction is based on the per capita income
differential adjusted by the purchasing power
parity and weighted by the income elasticity of
demand. In this case, the benefits transfer function
assumes the following form:
WTPbr�WTPeua�(PPPbr=PPPeua)e; (6)
where: PPPbr is the per capita income in Brazil
adjusted by the purchasing power parity of theReal (Brazilian currency); PPCeuais the per capita
income in the US adjusted by the purchasing
power parity of the US Dollar; e is the income
elasticity of demand.
4. Case study: application for three Brazilian
endangered species
Considering the methodology laid out in this
study, the objective at this point is to value three
endangered Brazilian species, namely the mico-
leao-preto (black lion tamarin) (Leontopithecus
chrisophygus ), the mico-leao-dourado (golden lion
tamarin) (Leontopithecus rosalia ), and a type of
cuıca (Micoureus demerarae ). These three specieswere specifically chosen, as mentioned earlier,
because they are the only ones for which Popula-
tion Viability Analyses (PVA) have been prepared
for Brazil, and thus their extinction probability
estimates may be more reliably used.
Fragmentation and loss of habitat are a serious
threat to biodiversity. This process, occurring on a
global scale, is probably the main threat faced bythe rich fauna of the Brazilian Atlantic Forest, the
so-called Mata Atlantica , the region along the
southeastern coast of Brazil, covering about a
million hectares. This is currently one of the most
endangered ecosystems on the planet, with only
about 5% of its original reserve still remaining
untouched, fragmented into smaller stretches of
land. Distinct types of marsupials and rodents maybe found in these areas, some surviving in isolated
areas, while others have grouped into metapopula-
tions. A metapopulation is defined here as a
population of a certain species that is restricted
to a specific area, as opposed to the population as
a whole. Although most species dealt with are not
endangered from a global perspective, frequentlythe loss of a population found in some segment of
forest may lead to an ecological extinction bring-
ing about considerable changes in the structure
and functioning of local communities.
However, as mentioned in the literature, a local
extinction is also a global one since observations
from islands would suggest that reductions in
continuous areas and isolation of habitats wouldincrease the rate of extinction. For this reason,
knowledge derived from the study of local popula-
tion extinction is likely to be useful in under-
standing the process of global extinction of a
species (Brito and Fernadez, 2000b). One of the
most endangered species in the Mata Atlantica
region is the Micoureus demerarae , which is a
small marsupial found in South America. Thisspecies can be found from Colombia to north-
eastern Argentina. In specific terms, the popula-
tion viability results presented in this study refer to
the study conducted for a metapopulation found
in a sub-region of the Mata Atlantica (Fernandez,
2000). Regarding the scenario upon which it was
based, the results show that this species is highly
endangered. The data show that the probability ofthis species becoming extinct over the next 100
years is approximately 45%. The worst case
scenario indicates that it is almost certain that
the species will become totally extinct.
Regarding the mico-leao-dourado , the PVA
research was conducted based on the metapopula-
tions located at the Poco das Antas reserve. For
the mico-leao-preto , the studies were based on themetapopulations found at the Caitetus and Morro
do Diabo Ecological Stations. With regard to the
research conducted at the Poco das Antas reserve
for the mico-leao-dourado metapopulation, the
results indicate that the probability of this meta-
population becoming extinct over the next 100
years is 15%, while the probability of the mico-
leao-preto metapopulation becoming extinct overthe next 10 years is 78%, indicating that this
species is highly endangered. The results for the
other regions were not conclusive (Seal et al.,
1990).
However, considering the objective of this study,
the determining of the viability function of a
certain species in not enough. According to Eq.
M.J. Cardoso de Mendonca et al. / Ecological Economics 46 (2003) 9�/1814
(4), it is necessary to determine the increment in
probability resulting from a variation in the size of
a species. In order to overcome this obstacle, said
variations shall be obtained from the variability
results obtained for different scenarios that may be
related either to situations of higher or lower
degrees of pessimism, as well as to endogenous
or exogenous aspects of the natural habitat, since
our objective here is to determine the preservation
management price from a variation in DSs in
relation to the current size of the species popula-
tion in the habitat. The variation in viability will
be obtained from the difference between the
viability values obtained for a more optimistic
scenario and those obtained for a scenario estab-
lished as a base. The idea here is that a more
optimistic scenario may be associated with some
positive effect regarding the size of the population
(Seal et al., 1990), considering that population size
is one of many PVA parameters. It is also possible
to determine the viability values produced by a
pessimistic scenario. In this case, the values are
derived from a negative shock upon the size of the
population. Table 1 presents the viability values
for three distinct scenarios.
The above results reveal that viability is very
sensitive to the hypotheses assumed for each
scenario. This may be observed in the sharp
difference in the results, especially when the
extremes of the intervals are considered. Also
regarding Table 1, the results indicate that for
any scenario, the probability of the mico-leao-
preto becoming extinct 100 years from now is
almost 100%.It must be pointed out that for the cuıca and the
mico-leao-preto , viability suffers a proportionally
larger impact in the pessimistic scenario than in
the optimistic one, while in the case of the mico-
leao-dourado the situation is not so imbalanced.
However, this may be easily explained. Note that
for the first two species, the PVA in the base
scenario is quite low, which is quite probably
related to the fact the current size of these two
populations is at a critical level. In this case, a
negative shock on the population has a strong
effect on viability, producing an important reduc-
tion in its value since the size of the population is
now at a level below critical. Lastly, the variation
in viability is arrived at from the difference
between the values obtained for the optimistic
and base scenarios.
Once the determining of the viability values, or
their variation, has been defined, the final task is
then to determine the WTP values, and the
diversity measurement for the species. Once these
values have been determined, we are now able to
determine the price for the species under study. As
was pointed out earlier, the WTP values to be used
in this study were derived from Loomis and White
(1996). In their study, the lower and upper WTP
values ranged between US$ 69 and US$ 1090, in
the case of a ‘lump sum’-type disbursement. The
use of ‘lump sum’ tax means that the funds
obtained from society would be immediately put
to use to implement the preservation program. In
other words, the resources obtained must be
allocated towards the execution of a specific
program. This is one way of increasing society’s
willingness to participate in such initiatives.
In Table 2, we shall present the adjusted values
according to the expression appearing in Eq. (6),
adjusted for Brazil. The WTP values are based on
Table 1
Viability scenario for endangered species
Common name of species (1) Pessimistic scenario (2) Base scenario (3) Optimistic scenario (4) Variation in viability DV (5)
Cuicaa 0.01 0.55 0.70 0.15
Mico-leao-preto b 0.05 0.50 0.70 0.20
Mico-leao-dourado c 0.84 0.88 0.96 0.08
The time frame for the mico-leao-preto is 50 years; for the two other species the time frame is 100 years.a Source: Brito and Fernadez (2000a).b Source: Seal et al. (1990).c Source: Kieruff (1993).
M.J. Cardoso de Mendonca et al. / Ecological Economics 46 (2003) 9�/18 15
the upper and lower values obtained in several
other studies found in the literature, calculated for
two distinct marginal income elasticity values. The
use of two values for the income elasticity of the
demand is due to the extreme sensitivity of the
results in relation to this parameter. The 0.50 value
was extracted from Ardila et al. (1998) in a specific
contingent valuation study for the Latin American
and Carribean regions. We also decided to attri-
bute a unitary value to income elasticity in order to
limit the interval to be obtained for the biodiver-
sity management price PM . Hence, the limit
established for PM diminishes the bias that may
exist because of the method adopted. A similar
procedure appears in Seroa da Motta et al. (2000).
At this point the task is to define a diversity
measurement for each one of the species being
valued. As per the previous section, there are
several ways of measuring biodiversity. However,
considering the scope of this study, we will adopt a
simple measurement methodology for biodiversity
as appears in Montgomery et al. (1999). This
measurement utilizes the weight of diversity ob-
tained from the taxonomic tree for each species.
Although the operational procedure used to com-
pute this index is relatively simple, the problem
resides in the fact that taxonomic information for
a given species is not readily available. Fortu-
nately, thanks to a project called ‘Tree of Life’ (in:
http://tolweb.org/tree/phylogeny), it is possible to
obtain, though to a limited extent, taxonomic
information for a large number of species. The
goal of this project is to produce information on
the diversity of living organisms, their history and
characteristics.
Although the information made available by the‘Tree of Life’ project is highly useful, certain
limitations still remain since said project is still in
a development stage. In the cases of the mico-leao-
preto and the mico-leao-dourado , the taxonomy
listed in the ‘Tree of Life’ does not go beyond the
genus Leontopithecus . Thus, we must assume for
the time being that both these species have the same
degree of biological diversity. Another limitingfactor is that there is no information available on
the small marsupial called Micoureus demerarae
beyond the genus Didelphimorphia , which is re-
presentative of the marsupial. In spite of all this, the
data obtained do offer some insights as to diversity.
Having presented the intermediate stages needed
to obtain the biodiversity preservation manage-
ment price, the final objective is to apply thismethod to each one of the species mentioned in
this study. This is done in Table 3. Some observa-
tions regarding this table must be made. Column 2
represents the most distant point from which it
was possible to consider the species dealt with the
‘Tree of Life’. The number of nodules and the
weight of diversity are concepts that were defined
above. However, it is the latter that defines thedegree of diversity. For more details, see Mon-
tgomery et al. (1999). Lastly, the valuing numbers
are listed in columns 5 and 6. These are derived
from the immediate application of Eq. (4). The
values appearing in each cell were obtained for the
two different income elasticity values appearing in
Table 2. The highest of these is related to the
income elasticity of 0.50. The lower and upperlimit calculations were based on the maximum and
minimum values appearing in Loomis and White
(1996) study, adjusted based on the benefits
transfer function, as presented in Eq. (6).
Although the results are sensitive to the value
used for income elasticity, the sharp difference in
the maximum and minimum levels comes from the
values extracted from Loomis and White (1996).So, in order for the values obtained to used as a
basis for public policy analyses, we suggest using
the more orthodox values, meaning those of lower
value. Another aspect that requires mentioning is
that the values found may also vary according to
the diversity measurement applied. It is therefore
necessary to pursue biological diversity measure-
Table 2
Parameter adjustment with the benefits transfer function for
Brazil (1999 US $)
Parameters Brazil USA
GNP per capita by PPC 7.037 17,900
WTP
Elasticity: 0.50 32.51 69.19
514.73 1,095.00
Elasticity: 1.00 15.28 69.19
241.86 1,095.00
M.J. Cardoso de Mendonca et al. / Ecological Economics 46 (2003) 9�/1816
ments that meet important requirements such as
invariance (Weitzman, 1992).
Some considerations may be made from Table
3. If we compare values found within columns (5)or (6) for the same income elasticity value, we note
that albeit the impact of the cuıca on the variation
in PVA is lower than that of the mico-leao-preto ,
the preservation management price of the cuıca is
nearly double that of the mico-leao-preto . The
reason for this is that the cuıca diversity weight is
slightly greater than that of the mico-leao-preto , as
can be observed in column (4) in Table 3. Due tothe fact the mico-leao species present the same
degree of biological diversity, the difference in
management price is only due to the variation in
PVA for each one of these species.
Lastly, the dynamic aspect of this line of approach
must be pointed out. Note that if the base scenario
values were to be those used for the pessimistic
scenario, the values for the first two species would bemuch greater than those obtained for the mico-leao-
dourado. Also, the extinction of a species belonging
to a certain taxonomic group increases the diversity
weight of the remaining species.
5. Final considerations
The objective of this study was to estimate
management prices for three Brazilian endangeredspecies based on the methodology developed by
Montgomery et al. (1999). This study presents the
upper and lower bounds values that define how
much an individual would be willing to pay, even
in a probabilistic manner, to finance a preserva-
tion program for a certain endangered species,
solely based on the management of a single
parameter for the species. The parameter analyzed
in this paper is related to the variation in the
current size of the species. The values obtained
serve as parameters to analyze endangered species
preservation policies, for if policy makers decide to
impose a value higher than the one proposed, it
would be unlikely that society would go along.
From 1985 to 1996, the Brazilian government,
both on the state and federal levels, invested
approximately US$ 33 million in preservation
programs (MMA, 1998). If international sources
were to be included in this estimate, the amount
invested in these projects would reach US$ 135
million. Considering the total management price
for the three species, estimated at the lower WTP
limit and unitary income elasticity, this value is
approximately US$ 10 per household.3 If we also
consider that the number of Brazilian households
is about 44 million, the expenditure on these three
species could reach US$ 440 million. This exercise
has thus demonstrated that total government
preservation spending in Brazil is apparently
much lower that what would be considered
socially desirable, with regard to the three species
analysed in this study.
It must be pointed out that one of the factors
that limit the reach of this proposal is the fact that
the results obtained are extremely sensitive to some
of the model’s parameters, among which are the
ways in which biological diversity is defined and
the several scenarios of future viability.
3 This value is obtained from the sum of the management
prices for the three species under study.
Table 3
Degree of diversity by taxonomy and management price of the species (1999 US$)
Common name of spe-
cies (1)
Genus (2) Nodules in the taxonomic
tree (3)
Weight of diversity
(4)
Price lower limit
(5)
Price lower limit
(6)
Cuıca Didelphimorphia 14 2.64 12.87 203.83
6.05 95.78
Mico-leao-preto Leontopithecus 37 1.00 6.50 105.00
3.06 48.37
Mico-leao-dourado Leontopithecus 37 1.00 2.60 41.18
1.22 19.35
M.J. Cardoso de Mendonca et al. / Ecological Economics 46 (2003) 9�/18 17
Together with the type of individual speciesprotection study conducted here, there is also
another type of study that deals with overall
biome protection. Some of these studies share the
viewpoint that would be the more consistent way
of dealing with the biological preservation pro-
blem. However, several aspects must be analyzed.
It could be argued that there is not necessarily a
trade-off between the two, since by preserving aspecies, the habitat is also being preserved. An-
other important issue is that the cost involved in
protecting the biome is, by definition, greater than
the cost of protecting a species. Thus, the adoption
of specific programs for species is a much more
viable alternative in economic terms. Frequently,
the pressure exerted upon the habitat is exogenous
in nature, and thus more difficult to control,stimulating specifically oriented actions. Lastly, it
is important to keep in mind that the logic behind
environmental protection is not immune to pre-
servation cost/benefit analyses. It is then possible
that costs involved in the complete preservation of
a biome may end up supplanting, from a social
perspective, the current benefits, making it all the
more difficult to sell the preservation proposal tosociety. Considering these issues, it is reasonable to
affirm that the determining of an endangered
species management or protection price is fully
supported within environmental economics.
References
Ardila, S., Queiroga, R. e Vaugham, W.J., 1998. A Review of
the Use of Contingent Valuation Methods in Project
Analysis at the Inter-American Developing Bank. Report
of Vanderbilt University, Nashville.
Bevers, M., Hof, J., Kent, B., Raphael, M.G., 1995. Sustainable
forest management for optimizing multispecies wildlife
habitat. Natural Resource Modeling 9 (1), 1�/24.
Brito, D., Fernadez, F., 2000a. Metapopulation viability of the
marsupial micoureus demerarae in small atlantic forest
fragments in south-eastern Brazil. Animal Conservation 3,
201�/209.
Brito, D., Fernadez, F., 2000b. Dealing with extinction is
forever: understanding the risks faced by small populations.
Ciencia e Cultura 52 (3), 161�/170.
DiMasi, J.A., Hansen, R.W., Grabowsky, H.G., Lasagna, L.,
1991. Cost of innovation in pharmaceutical industry.
Journal Health Economy 10, 107�/142.
Krajewsky, C., 1989. Phylogenetic relationships among cranes
(Gruiformes: gruidae) based on DNA hybridization. The
Auk, CVI, 603�/618.
Lamberson, R.H., McKelvei, R., Noon, B., Voss, C., 1992. A
dynamic analysis of spotted owl in a fragment forest.
Conservation Biological 6, 505�/512.
Loomis, J.B., White, D.S., 1996. Economic benefits of rare and
endangered species: summary and meta-analysis. Ecological
Economics 18 (3), 197�/206.
Kieruff, M.C.M., 1993. Avaliacao das Populacoes Selvagens de
Mico-leao-dourado Leontopithecus rosalia e Proposta de
Estrategia de Conservacao. MSc Thesis, Universidade
Federal de Minas Gerais, Belo Horizonte, MG.
Markandya, 1998. The valuation of health impacts in developing
countries. Planejamento e Polıticas Publicas v. 18, 119�/143.
Master, L., 1991. Assessing threats and setting priorities for
conservation. Conserving Biology 5, 559�/563.
May, P.H., Veiga Neto, F.C., Pozo, O.V.C., 2000. Valoracao
Economica da Biodiversidade: estudo de casos. In: http://
www.mma.gov.br..
MMA-Ministerio do Meio Ambiente, dos Recursos Hıdricos e
da Amazonia Legal. Primeiro Relatorio Nacional para
Convencao sobre Diversidade Biologica. 1998
Mitchell, R., Carson, R., 1989. Using surveys to value public
goods. Resourses for the Future, Washington, DC.
Montgomery, C.A., Pollack, R.A., Freemarck, K., White, D.,
1999. Pricing biodiversity. Journal of Environmental Eco-
nomics and Management 38, 1�/19.
Seal, U.S., Ballou, J.D., Claudio Valladares-Padua., 1990.
Populations extinction model of lion tamarins in currently
protected areas. Leontopithecus, Population Viability Ana-
lysis, Workshop Report, Captive Breeding Specialist Group,
Belo Horizonte, Brasil.
Seroa da Motta, R., Ortiz, R.A., Ferreira, S.F., 2000. Health
and economic values for mortality cases associated with air
pollution in Brazil. Expert Workshop on Assessing The
Ancillary Benefits and Costs of Greenhouse Gas Mitigation
Strategies, Washington, DC, 27�/29, March.
Shaffer, M.L., 1983. Minimal population sizes for species
conservation. Bioscience 31, 131�/134.
Soule, M.E. (Ed.), Viable Populations for Conservation. Cam-
bridge University Press 1987.
Vane-Wright, R.K., Humphries, C.J., Williams, P.H., 1991.
What to protect? systematic and the agony choice. Con-
servation Biological 55, 235�/254.
Weitzman, M., 1993. What to preserve? an application of
diversity theory to crane conservation. The Quarterly
Journal of Economics, 108, 157�/183.
Weitzman, M., 1992. On diversity. The Quarterly Journal of
Economics, 107, 363�/406.
M.J. Cardoso de Mendonca et al. / Ecological Economics 46 (2003) 9�/1818