1) The document discusses whether agricultural intensification can save tropical forests by reducing the need to clear more forest land for agriculture.
2) It presents two opposing views - the "Borlaug world" view that higher agricultural yields will reduce deforestation, and the "Jevons world" view that higher yields could increase deforestation by making agriculture more profitable.
3) The document concludes that whether agricultural intensification reduces or increases deforestation depends on the demand elasticity for agricultural products - inelastic demand favors forest preservation, while elastic demand could increase deforestation. Proactive policies are still needed to ensure forest conservation.
1. Will agricultural intensification
save tropical forests?
Arild Angelsen
School of Economics and Business,
Norwegian University of Life Sciences (UMB), Ås , Norway
& CIFOR , Bogor, Indonesia
arild.angelsen@umb.no
Warzaw
12.11.2013
2. School of Economics and Business
NORWEGIAN UNIVERSITY OF LIFE SCIENCES
Three major roles of agriculture in climate change
mitigation
1. Agric land encroaching forests (defor & A/R)
2.
Fluxes on (existing) agric land
3.
Substitution effects from changes in agric production (e.g.
biofuel replacing fossil fue: l)
Focus only on 1., and ask one main question
Can/will agric intensification save forests?
Land consuming vs. land sparing (Jevons vs. Borlaug)
(A related: land sharing vs. land sparing)
Agric intensification (increase output/ha = yield):
– Technological progress (more outputs with same inputs)
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– Factor substitution (more inputs per ha)
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3. School of Economics and Business
NORWEGIAN UNIVERSITY OF LIFE SCIENCES
The Borlaug world
(the full belly or subsistence model)
Food
= Food
Food/pop * pop
= Food/ag land * ag land
Subs req. * pop
= yield * ag land
Ag land
= (subs req * pop) / yield
Land = ag land + forests
A simple theory of deforestation
Ag intensification (higher yield) reduce need for ag land
=> less encroachment into natural forests
Can be apllied at various scales (e.g. global food
equation)
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4. School of Economics and Business
NORWEGIAN UNIVERSITY OF LIFE SCIENCES
Example: cereals
1961-63
2006-08
Pct .
increase
Pop (bn)
3.13
6.62
111.6
Consumption
(kg per capita)
294.3
358.3
21.8
Area harvested
(mill ha)
653.7
697.2
6.7
Yield
1.41
3.40
141.5
Demand
Supply
Source: Stevenson et al. (2011),
based on: http://data.un.org/
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5. School of Economics and Business
NORWEGIAN UNIVERSITY OF LIFE SCIENCES
The Jevon world:
(A market/partial equilibrium/von Thünen model)
Define ag rent per ha as
profit = gross sales – costs
r = py – wl – qk –vd
$
p(rice), y(ield), w(age), l(abour) per ha, q(cost of k),
k(capital), v(distance costs per km & ha), d(istance)
Policy: reduce ag rent:
Lower yield will save
the forest!
Ag rent
Deforestation (d)
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6. School of Economics and Business
NORWEGIAN UNIVERSITY OF LIFE SCIENCES
Can the two worlds be reconciled?
Two very different logics
– Subsistence model and global food equation:
higher yield saves forests
– von Thünen model:
higher yield gives encroachments into forests
How can they be reconciled?
1. Extending global food equation
2. Market demand conditions
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7. School of Economics and Business
NORWEGIAN UNIVERSITY OF LIFE SCIENCES
National deforestation equation (NDE) (Angelsen, 2010)
Pop * (Food cons/Pop) = (Food cons/Food prod) * (Food
prod/Ag prod) * (Ag prod/Ag land) * (Ag land/Forest) *
Forest
deforestation ≈ pop growth + ∆ food cons per capita - ∆
self-sufficiency ratio (inverse) - ∆food share - ∆yield ∆ag/forest ratio
One among several factors
Yield change can affect other factors:
Self sufficiency (more competitive)
Food share, e.g. biofuel
Be careful with identities:
they are always correct (a warning sign!)
cannot assume ceteris paribus (other factors will change)
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8. School of Economics and Business
NORWEGIAN UNIVERSITY OF LIFE SCIENCES
It’s the demand elasticity, stupid!
Demand elasticity: how sensitive is demand to price
changes (1% ∆ price => x% ∆ quantity)
What is the impact of technological change (supply shift)?
Inelastic (quantity given – 1. Borlaug world: B) vs.
Elastic (price given – 2. Jevons/von Thünen world: C)
Price
Perfectly
inelastic
demand
Supply
Supply after
tech progress
Perfectly
elastic
demand
A=C
B
A=B
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C
Quantity
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9. School of Economics and Business
NORWEGIAN UNIVERSITY OF LIFE SCIENCES
What is the demand elasticity?
Depends on:
How widespread is the tech change; market share
Scale of analysis:
– The higher scale, the more inelastic demand
Type of commodity:
– Inelastic: food
– Elastic: non-food with substitution (e.g. rubber, biofuel)
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10. School of Economics and Business
NORWEGIAN UNIVERSITY OF LIFE SCIENCES
Empirical studies – macro level
Area & yield links at national level over time (by crop or
total)
Ewers et al. (2009):
– 23 staple crops, 1979-1999, 124 countries
– The yield-area elasticity
– Borlaug hypotheses: -1
– Developing countries: -0.152 (t=-1.78)
– Developed countries: -0.089 (t=-0.57)
– Weaker and non-significant for total cropland
– Weak tendency in developing countries for the per
capita area to decline as cropland increase
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10
11. School of Economics and Business
NORWEGIAN UNIVERSITY OF LIFE SCIENCES
… empirical studies
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filled: developing; countries
open: developed countries
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12. School of Economics and Business
NORWEGIAN UNIVERSITY OF LIFE SCIENCES
Case studies summary
Reduced
(win-win)
Intensive (high)
Constrained
Local
Yield increasing
Local,
segmented
Intensive
(lowland)
Global
Short term
Impact on
deforestation
L & K intensity
Farmer
characteristics
Output market
Technology
Labour market
Sector experiencing
tech. change
Scale of adaptation
Time horizon
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Increased
(win-lose)
Saving (low)
Well-off
Global
Cost-saving
Mobile
(migration)
Frontiers
(upland)
Local
Long term
12
13. School of Economics and Business
NORWEGIAN UNIVERSITY OF LIFE SCIENCES
Win-win outcomes
Agricultural technologies suited specifically for forest-
poor areas
Labour-intensive technologies where labour is scarce
and migration limited
Promote intensive systems where farmers are also
involved in low-yielding extensive farming practices
Agricultural technologies that substantially raise the
aggregate supply of products with inelastic demand
BUT, some of win-win technologies are least likely to be
adopted by farmers
– Produce commodities for local markets where prices
quickly drop
– Choose technologies that use the most scarce resources
intensively
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14. School of Economics and Business
NORWEGIAN UNIVERSITY OF LIFE SCIENCES
Win-lose outcomes
Agricultural technologies that encourage production
systems that require little labour and/or displace labour
New agricultural products for sale in large markets in
labour-abundant contexts
Eradication of diseases that limit agricultural expansion
Technological changes in forest margin areas with
rapidly growing labour forces
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15. School of Economics and Business
NORWEGIAN UNIVERSITY OF LIFE SCIENCES
Some trends
1. Globalization – increased
market integration; more likely
to be price takers
2.
land sparing
less likely
Deforestation driven by
commercial actors
3. Separation of forest and agric
land
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agric int.
less important
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16. School of Economics and Business
NORWEGIAN UNIVERSITY OF LIFE SCIENCES
So what?
Mistake 1: assume that technological change & agric
intensification will save forests
Mistake 2: be against new technologies & intensification
because it may put pressure on forests
Agric intensification needed for a number of reasons, but
forest conservation is not on top of that list
BUT, will enable and make other forest conservation
measures more effective and politically feasible
It’s not the solution, but part of the package
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17. School of Economics and Business
NORWEGIAN UNIVERSITY OF LIFE SCIENCES
Deforestation policies – what works
Selective agric technologies
Agric rent in frontier areas
– Roads
– Subsidies
Forest rent and its capture
– Community management
– PES schemes
Regulations
– Protected areas (enforcement)
– Land use planning
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18. School of Economics and Business
NORWEGIAN UNIVERSITY OF LIFE SCIENCES
Will agricultural intensification
save tropical forests?
“… no one can guarantee that
economic development –
whether agriculturally driven
or not – will lead to a forest
transition and an end to
inappropriate deforestation.
Informed proactive policies will
have to do that.”
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