1CASOS (July 2000)
A decision process model mixing rational A decision process model mixing rational anticipations and social influences : the example of anticipations and social influences : the example of
agri-environmental measure adoption in Breadalbane agri-environmental measure adoption in Breadalbane ESA (Scotland)ESA (Scotland)
Guillaume Deffuant, Frédéric Amblard, Nils Ferrand (Cemagref, France)
Nigel Gilbert (university of Surrey, UK)
Gérard Weisbuch (Ecole Normal Supérieure, France)
CASOS (July 2000)
Agri-environmental measuresAgri-environmental measures
+ $$
Farmer
• Pilot zones from 1986Pilot zones from 1986• Generalised to all Europe in 1992Generalised to all Europe in 1992
CASOS (July 2000)
European projectEuropean project
• First goal : evaluate the model First goal : evaluate the model on the paston the past
+ $$
• Then evaluate prescriptive useThen evaluate prescriptive use
• Breadalbane ESA ScotlandBreadalbane ESA Scotland
CASOS (July 2000)
Breadalbane ESABreadalbane ESA
• 150 farms, mainly 150 farms, mainly sheep, average size : sheep, average size : 650 ha650 ha
• 39 farmers 39 farmers interviewedinterviewed•10 re-interviewed10 re-interviewed•10 interviews with 10 interviews with institutional actorsinstitutional actors
• First ESA : From 1986 to 1992First ESA : From 1986 to 1992• Second ESA : From 1992 to 1999Second ESA : From 1992 to 1999
CASOS (July 2000)
Breadalbane ESA : implementationBreadalbane ESA : implementation
• End 1986 :End 1986 :•Press : first rough Press : first rough description of the description of the measuremeasure•The measure is about The measure is about landscape and landscape and biodiversitybiodiversity
CASOS (July 2000)
Breadalbane ESA : implementationBreadalbane ESA : implementation
• End 1986 :End 1986 :• SAC : contact 10 SAC : contact 10 "leader" farmers and "leader" farmers and promote the measurepromote the measure• More financial More financial information information
CASOS (July 2000)
• March 1987 :March 1987 :• Organisation of the Organisation of the official presentation official presentation meetingmeeting•All farmers invitedAll farmers invited•Participation 50%Participation 50%
Breadalbane ESA : implementationBreadalbane ESA : implementation
CASOS (July 2000)
Breadalbane ESA : implementationBreadalbane ESA : implementation
• The interested farmer calls The interested farmer calls SAC advisorSAC advisor
• SAC advisor comes to the SAC advisor comes to the farm and makes to ecological farm and makes to ecological diagnosisdiagnosis
• The still interested farmer The still interested farmer calls SAC advisorcalls SAC advisor
• The advisor comes to the The advisor comes to the farm and the farm plan is farm and the farm plan is negotiatednegotiated
0
20
40
60
80
100
1987 1988 1989 1990 1991 1992
adoption %
• From April 87 to End 92:From April 87 to End 92:
CASOS (July 2000)
The modelThe model
CASOS (July 2000)
The decision model : variablesThe decision model : variables
d
a
-1 +1
• Uncertain anticipations of Uncertain anticipations of impacts (or impressions)impacts (or impressions)
• IncomeIncome
• MotivationsMotivations
• IndependenceIndependence a
d
-1 +1
a
d
-1 +1
• NatureNature
CASOS (July 2000)
The decision model : InteractionsThe decision model : Interactions
Before meetingBefore meeting
F’F
a a’
F F’
a a’a
d
d’
d
After meetingAfter meeting
dd’
CASOS (July 2000)
The decision model : rational The decision model : rational evaluationevaluation
• The impact on income is evaluated "rationally" with the advisor when the farm plan is established
• The calculation of this impact takes into account :– the size of the farm– the level payments– the level of the associated costs
CASOS (July 2000)
The decision model : decision stagesThe decision model : decision stages
• mm..aa < < TT11• Farmer not interested by the measure.
• TT11 < < mm..aa < < TT22• Interested,• Discussions with colleagues
• mm..aa > > TT22• Interested,• willing to begin the procedure
• mm..aa - - mmrr.d.dr r >T>T33 • Ready to adopt•can if procedure completed
CASOS (July 2000)
Initialisation of anticipated impactsInitialisation of anticipated impacts
d
a-1 +1
• Uncertain anticipations Uncertain anticipations (or impressions)(or impressions)
• IncomeIncome
• MotivationsMotivations
• IndependenceIndependence
• NatureNature
d
a-1 +1
d
a-1 +1
CASOS (July 2000)
Initialisation of the motivationsInitialisation of the motivationsNature
0 5 10 15
0
1
2
3
4
Revenu
0 5 10 15
0
1
2
3
4
Indépendence
0 10 20 30
0
1
2
3
4• Motivation Motivation distribution for distribution for interviewed farmsinterviewed farms
• Randomly Randomly affected to non affected to non interviewed interviewed farmsfarms
CASOS (July 2000)
Social networkSocial network
• link probability = exp (- link probability = exp (- DD((FF,,F'F'))))• Average link number : 4.8Average link number : 4.8
CASOS (July 2000)
Institutional messagesInstitutional messages
d
a-1 +1
d
a-1 +1
d
a-1 +1
• PressPress
• IncomeIncome • IndependenceIndependence • NatureNature
d
a-1 +1
d
a-1 +1
• SACSAC
CASOS (July 2000)
First resultsFirst results
CASOS (July 2000)
test 4 40-50
0
20
40
60
80
100
120
140
1 253 505 757 1009 1261 1513 1765 2017 2269
phase 1
phase 2a
phase 2b
phase 2bc
phase 3
Messages from the pressFirst messages from SAC
Meeting
Beginning of advisor visits no interest
discussing
visit ready
non adopteradopter
Example of resultsExample of results
CASOS (July 2000)
Average fitting the first adoption pointsAverage fitting the first adoption points
0
10
20
30
40
50
60
70
80
90
1000
234
468
702
936
1170
1404
1638
1872
2106
2340
une simulation
moyenne
données
number of adopters
average
data of adoption
CASOS (July 2000)
Fitting first point and last point Fitting first point and last point
0
20
40
60
80
100
120
1 265 529 793 1057 1321 1585 1849 2113 2377
une simulation
Moyenne
Données
number of adopters
average
data of adoption
CASOS (July 2000)
ConclusionConclusion
• Progressive refinement of the model :– institutional scenarios– dynamic model– more impacts and motivations
• Study for the use in a prospective purpose
