rate.
11
Perhaps the best perspective is to recognize that EBA is better at evaluating regional impacts
of various projects, whose implementation is often in the name of sustainable development and envi-
ronmental protection that almost certainly pro- vides positive net benefits at the supraregional
level.
Because of these potential weaknesses of EBA, it would be premature to abandon CBA as one
methodology to be used in project evaluation, and the intention of this paper is not to suggest that
EBA should be the sole means by which develop- ment projects are evaluated. Kirkpatrick and
Weiss 1996 call for a ‘mixed team approach,’ pointing out that ‘‘…there will be certain types of
projects which should be seen in terms of the achievement of a set of objectives, which cannot
be converted readily into the monetary numeraire of conventional appraisals.…’’ By emphasizing
employment, equity, and most importantly, sus- tainability over the maximization of monetary net
benefits, EBA can be part of the cultural shift inherent in the ‘methodological pluralism’ that
Norgaard 1989 argues is necessary for ecological economics.
4. An application
4
.
1
. Background Some of the benefits and challenges of EBA are
illustrated in the following application of the anal- ysis to alternative economic activities in Yucata´n,
Mexico. While the data employed are rudimen- tary, they are sufficient for rough calculations that
permit comparison between the results achieved from EBA and CBA for alternative activities.
12
Agriculture on the Yucata´n Peninsula is charac- terized by a high degree of subsistence farming.
There are approximately 170 000 agricultural units on the peninsula, 95 of which are tradi-
tional farm units. These units employ in the neighborhood of 800 000 campesinos peasant
farmers and their families, approximately 35 of the total population of the peninsula Cuanalo de
la Cerda, 1995. Subsistence farming in the area uses the traditional Mayan milpa system, a diverse
production system the center of which is rota- tional, ‘slash-and-burn’ agriculture. Corn fields
intercropped with beans and squash of approxi- mately 2 ha are cleared from surrounding forests
via slash-and-burn. Fields are usually used for a period of 2 years, then allowed to revert back to
forest. Historically, the rotation period in the milpa system was 16 – 25 years, leading to suffi-
cient and sustainable productivity Teran and Rasmussen, 1994. However, recent population
increases combined with conversion of large areas to pasture for commercial cattle production is
cited as the primary factor for a shortening of rotation periods to 6 – 8 years, leading to de-
creased productivity, increased labor require- ments, and poor nutrition in campesino families
Cuanalo de la Cerda, 1995. Effects on forest health, productivity, and biodiversity have not
been studied, but it seems safe to assume that the effects have not been positive. Even though it is
no longer strictly practiced, ‘traditional milpa’ with a historic rotation period of 20 years is
analyzed below, largely for illustrative purposes, but also based on the conjecture that it is more
sustainable than the cattle ranching that has influ- enced its demise.
The Yucata´n Peninsula is also the location of several biosphere reserves. Apart from official
designation, these reserves receive very little direct governmental funding, and are instead managed
primarily by two NGO’s, Pronatura Penı´nsula de Yucata´n and Amigos de Sian Ka’an. Both groups
support small-scale projects within the biosphere reserves as part of their overall environmental
conservation programs Morales, 1995; Pronatura Penı´nsula de Yucata´n, 1995. In particular,
Pronatura sponsors ongoing efforts in the Calak- mul Biosphere Reserve to foster sustainable devel-
11
This is, of course, because the developing countries in which much of such resources are located are poor. Incorpora-
tion of global positive externalities into local policy implemen- tation represents a transfer from the developing region to the
rest of the world that developing regions, by definition, can ill-afford. Overcoming this transfer through compensation is
an equity matter that is independent of both EBA and CBA.
12
The data used to calculate figures presented here are available from the author.
opment that will slow incursions into some of the last moist tropical forests on the Southern Yu-
cata´n Peninsula; examples include aquaculture projects, the use of ‘improved milpa’ and eco-
tourism projects, along with educational efforts. Cuanalo de la Cerda 1995, 1996a are studies of
‘improved milpa’ techniques. They examine the effects of improved technology and investment on
milpa productivity, with an eye toward reversing downward trends in campesino nutritional levels
and rotation periods, and eliminating the burning of fields as part of the rotational structure of
milpa agriculture. Cuanalo de la Cerda 1996a shows that it is possible, using improved technol-
ogy fertilizers, limited herbicide use, nitrogen- fixing legumes, animal husbandry and modest
investments, to make these milpa units sufficiently productive to raise nutritional levels to an accept-
able level. These efforts provide a rich context for the application of EBA, and investigation into
their successes and challenges was the impetus for the development of the methodology, so improved
milpa is also analyzed below.
Cattle ranching is one of the major competing agricultural land uses in Yucata´n Peninsula Cua-
nalo de la Cerda, 1995; Santos and Anderson, 1995. While most ranches in Yucata´n have some
diversified production of agriculture, on average a Yucatecan ranch has only 4 of its land in forest.
Cattle are raised on a mixture of native and non-native grasses along with cultivated canes
and fodder from ramon trees Brosimun alcas- turm. Supplementary fodder is purchased at
times by most ranches, usually during extended drought years, although at the time of the study,
Santos and Anderson 1995 found that 73 of the ranches in their sample had not purchased
supplementary fodder in the previous 12 months. Some cattle are pastured on a single field continu-
ously, but most are rotated. The majority 79 of ranches burn their fields annually to discourage
unwanted grass and bush species Santos and Anderson, 1995, so rotation is to permit recovery
of grasses, not full forests. There are several rea- sons why cattle ranching masks an appropriate
choice of alternative to milpa in the application of EBA. First, cattle ranching is widely cited as
being associated with large scale deforestation in the neotropics see, for example, Parsons, 1993;
Schelhas, 1996; Moran et al., 1996, and thus is an indirect cause of environmental degradation. Ad-
ditionally, cattle ranching uses relatively little labor, and this is more likely to produce illumi-
nating findings using EBA relative to CBA.
4
.
2
. Employment-based analysis While no specific project in Yucata´n has yet to
use EBA ex ante, several researchers have gath- ered data that permit use of both EBA and CBA
methodologies in the evaluation of two forms of milpa agriculture and cattle ranching.
13
EBA of the milpa is the most straightforward. Cuanalo de la Cerda 1996a uses a sample con-
sisting of 34 volunteer families from the commu- nity of Yaxcaba´. Because all members of the
family, other than the very young and very old, work in one or more components of the milpa,
population support as opposed to jobs is the appropriate unit of measure. Family size averages
6.73 members per family. Each family requires 2 ha of cornbeansquash fields every 2 years; as-
suming a rotation period of 20 years, a family requires 20 ha for fields. Home garden and living
space sizes vary, but a liberal estimate would be 1 ha.
14
Thus, a family requires 21 ha to sustain it indefinitely. Using an arbitrary measure of 100 ha
as a land base, we arrive at a figure of 32.05 people per 100 ha per year. Since this method of
production is sustainable indefinitely, our choice of time period is arbitrary. Using 20 years as a
time base, we arrive at 641 people-years over the 20-year period. This is the fundamental figure to
be derived from a typical EBA.
‘Population support’ externalities are probably a net positive through the maintenance of forested
areas that are between field use and used for
13
I am extremely grateful to Dr Heriberto Cuanalo de la Cerda of Centro de Investigaciones y de Estudios Avanzados
CINVESTAV, Merida, and Luis Araujo Andrade of the Facultad de Economı´a, Universidad Autonoma de Yucata´n
UADY, for graciously providing me with data from their studies.
14
No rotation is required for home gardens and living space.
hunting and gathering Teran and Rasmussen, 1994, but are assumed to be negligible for the
purposes of the analysis here. Note, however, that at any one time 85.72 ha out of our arbitrary 100
ha is in forest or forest regeneration. Campesinos do earn income both through the sale of some
excess production and temporary migration to urban areas for the purpose of day laboring Cua-
nalo de la Cerda, 1996a. The population-sup- ported figure captures the benefits of these
activities to the families themselves. Given the excess production levels of citrus and surplus labor
in the region, influence of these activities on the regional economy may not be completely negligi-
ble, but is probably quite small and safe to ignore.
Under the improved milpa system and assuming an 8 year rotation, a family requires only 9 ha of
land to support it indefinitely; using all of other assumptions above, a project of improved milpa
leads to 74.78 people-years per 100 ha, or 1496 people-years over the 20-year span.
While improved milpa involves a degree of up-front investment, farmers in Cuanalo de la
Cerda 1996a were able to pay back all loans within several years; excess production thereafter
accrued to that family and led to improved nutri- tion. Population support externalities are of a
slightly greater concern in the improved milpa system. The use of fertilizers, and in particular
herbicides Gramoxone, may have negative exter- nalities and in a longer period of time prove to be
unsustainable. Gramoxone is a form of the herbi- cide paraquat, which is highly toxic to humans
orally, dermally, and via inhalation, birds, and crustaceans; its persistence qualities are unknown
Briggs and Staff of the Rachel Carson Council, 1992. Plants are relatively slow to develop resis-
tance to herbicides, but at least one study found limited strains of weeds resistant to paraquat Ra-
dosevich, 1983. However, Cuanalo de la Cerda 1995 tracks production levels for a single farm in
Campeche using an improved milpa system, in- cluding the use fertilizers and herbicides, over an
11-year period and finds no declines in productiv- ity. The lack of surface water in Yucata´n also
lessens the degree to which herbicide use can contribute to non-point source pollution. Many
researchers increasingly recommend the use of integrated pest management IPM, in which non-
pesticide pest control is favored and employed first, but does incorporate the use of pesticides in
extreme cases Postel, 1987; Lerner, 1997. It is not clear whether pesticide use in the Cuanalo studies
was part of an IPM. However, a primary purpose of the use of fertilizers and herbicides in improved
milpa systems is to eliminate field burning; given that field burning produces a host of negative
externalities that could influence population sup- port, fertilizer and herbicide use may be no worse
than the alternative. In a larger sense, nonetheless, the introduction of such methods may seem coun-
ter to sustainable development. Given current po- litical and economic trends in Mexico, however,
the limited use of fertilizers and herbicides seems to be an important part of raising nutritional
levels to an acceptable level. Given the lack of information, assume for the calculations here that
the limited herbicide and fertilizer use poses no significant negative population support externali-
ties and no negative impact on sustainability; if this were an actual full-scale EBA, more data and
sensitivity analysis would be highly desirable.
Turning to cattle ranching. Santos and Ander- son 1995 divide the ranches in their sample into
small ranches 1 – 40 head of cattle, medium 41 – 160 head, and large 161 – 2000 head, and find
that each stratum exhibits different characteristics in terms of importance of cattle ranching as a
source of income, field rotation methods, supple- mentation of fodder, and other features. In partic-
ular, they find that larger ranches are more dependent on cattle ranching as a source of in-
come as opposed to smaller ranches where families and workers may earn income off the
ranch. This feature suggests that data from the large ranch strata are most appropriate to use in
order to isolate cattle ranching as an economic alternative to milpa. Furthermore, the government
policy encouraging large ranches makes the large ranch strata the most appropriate in terms of
policy analysis.
15
The larger ranches also tend
15
The fundamental findings of EBA of cattle ranching presented below, however, do not differ greatly amongst all
three stratum.
to use labor more efficiently, which should further highlight distinctions between the results of EBA
and CBA. The large ranches in Santos and Anderson
1995 consist of an average of 545 ha. According to Cuanalo de la Cerda 1995, many of these
large ranches are managed by overseers encar- gados for absentee landowners, so that there is
probably a considerable amount of local and re- gional capital flight. The numbers in Santos and
Anderson 1995 support this contention, as they find that the average large ranch maintains 0.5
non-salaried family workers. This labor is sup- plemented by an average of 2.6 fixed salary work-
ers and 5.1 conditional workers. Ranch owners support a total of 7 family members on average,
while the figure of 6.73 obtained from Cuanalo de la Cerda 1996a is used for salaried workers, and
conditional workers, and conditional workers are assumed not to have families or obtain their
primary support from off the ranch.
The sustainability of these ranches and there- fore whether or not cattle raising might give way
to other activities over the 20-year period of anal- ysis is mostly a matter of conjecture. While
ranching has been active on the peninsula for centuries, Cuanalo de la Cerda 1995 claims that
the burning of fields is leading to desertification, although there have been no formal studies con-
ducted. While few ranches use fertilizers, pesti- cides, or herbicides Santos and Anderson, 1995,
one would have to believe that the massive burn- ing of fields in a dry tropical environment with
poor soils would lead to declines in productivity. These conjectures notwithstanding, let us use the
most optimistic assumption that large ranches in Yucata´n have sufficient land to rotate their cattle
in such a fashion that production in sustainable indefinitely and does not produce significant local
population support externalities. Using the same 20-year period as was used with milpa, we obtain
the figure of 5.48 people per 100 ha, or 109.62 people-years over 20 years.
16
4
.
3
. Benefit-cost analysis Traditional milpa on a 20-year rotation is
rarely, if ever, actually practiced, so that CBA is not available for that development option.
17
Re- garding ‘improved milpa,’ Cuanalo de la Cerda
1995 calculates a benefit-cost ratio of 1.54 for an integrated milpa system, while the best combina-
tion of fertilizers, nitrogin fixing legumes and no field burning in Cuanalo de la Cerda 1996b
results in a benefit-cost ratio of 1.93.
18
These studies were relatively simple in nature; for exam-
ple, they did not incorporate any effects of exter- nalities, impact on wage levels, or non-monetary
costs and benefits. They also assume a wage rate of 15 new pesos per day, which may be some-
what optimistic, given the high levels of unem- ployment in Yucata´n.
Benefit-cost data are extremely limited for cattle ranching in Yucata´n. Araujo 1995 collected data
over 3 years at a single ranch in Yucata´n. His data result in a benefit-cost ratio of 2.12. As with
CBA on improved milpa, data on externalities, wage effects, and non-monetary costs and benefits
were not collected. Thus, while studies for both types of production are somewhat incomplete
Table 1 EBA and CBA for alternative agricultural activities, Yucata´n
a
EBA, people-years for CBA,
100 ha, 20 years benefit-cost
ratio Traditional
– 641
milpa 1.54
1495.6 Improved milpa
Cattle ranching 2.12
109.6
a
Sources, Araujo 1995, Cuanalo de la Cerda 1996a,b.
17
Cuanalo de la Cerda 1996a reports a cost-benefit ratio of 0.64 for unimproved milpa using the 6 – 8 year rotations.
18
Note that this is just for the corn-bean-squash field com- ponent of the ‘improved milpa’. Cuanalo de la Cerda 1996a
reports cost-benefit ratios greater than one for all other com- ponents fruit and vegetable production, pig and chicken
production, apiary of the improved milpa system.
16
If part-time workers are supporting full families with their labor on cattle ranches, the resulting figures are 10.89 people
per 100 years, or 217 people-years per 100 ha.
and over small sample size, they are suitable for comparison.
4
.
4
. Analysis of findings The calculations derived above are summa-
rized and presented in Table 1. The findings highlight the value EBA: using just monetary
benefits and costs CBA, cattle ranching ap- pears to be a more profitable economic enter-
prise in Yucata´n. But because it uses large quantities of land and relatively little labor, cat-
tle ranching supports a relatively small popula- tion on a given measure of land. To the extent
that a sustainable development project is to provide local people with alternatives to envi-
ronmentally degrading activities, or greater em- ployment opportunities in general, traditional
milpa should be preferred to cattle ranching, and improved milpa should be preferred to tra-
ditional milpa.
Despite the figures obtained, a number of as- sumptions made in these calculations probably
lead to a masking of the full analytical potential of EBA as described in Section 2 above. In par-
ticular, the assumption that a cattle ranching is fully sustainable over 20 years seems very opti-
mistic, even in the case of large ranch optimally rotating its fields. More likely, the representative
100 ha in the case of cattle ranching would not stay as productive over the course of 20 years,
and alternative economic activities would take place on it, most likely in the course of the land
returning to forest. This would result in even lower figures for people – years in the case of
cattle ranching. Similarly, it is possible that the use of fertilizers and herbicides in the improved
milpa system could have a negative effect on population support over the course of 20 years,
resulting in lower person – years for that option. Resolving these uncertainties could be done
through obtaining more data, or calculating multiple figures for each option based on a vari-
ety of different assumptions.
The figures in Table 1 also demonstrate EBA’s usefulness in analyzing different overall
economic activities
as opposed
to specific
projects. The analysis suggests that if Mexican policymakers are concerned about sustainability,
increased employment for the poor, and a more equitable distribution of income, they should
promote traditional milpa over cattle production and improved milpa over traditional milpa.
5. Conclusions and suggestions for future research
