Will agricultural intensification save tropical forests? - Arild Angelsen

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

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)
www.umb.no
– Factor substitution (more inputs per ha)

2



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)
www.umb.no

3



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/
www.umb.no

4



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)
www.umb.no

5



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

www.umb.no

6



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)
www.umb.no

7



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
8



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)

www.umb.no

9



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

www.umb.no

10



… empirical studies

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filled: developing; countries
open: developed countries
11



Case studies summary
Reduced
(win-win)
Intensive (high)

Impact on
deforestation
L & K intensity

Increased
(win-lose)
Saving (low)

Constrained

Farmer
characteristics
Output market

Well-off

Technology
Labour market

Cost-saving
Mobile
(migration)
Frontiers
(upland)
Local
Long term

Local

Yield increasing
Local,
segmented
Intensive
(lowland)
Global
Short term

Sector experiencing
tech. change
Scale of adaptation
Time horizon
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Global

12



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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13



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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14



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

15



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

www.umb.no

16



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

www.umb.no

17



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.”

www.umb.no

18

Will agricultural intensification save tropical forests? - Arild Angelsen

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