Candidate 102 Model file
abbdca15-a029-4ba1-a99d-e0db23c52390
isee systems, inc.
Stella Architect
2000
2050
4
1
dmnl
unitless
fraction
person
persons
kg
kilogram
yr
year
People who have not adopted meat substitutes and are not currently considering adoption. Increases through population inflow and decreases as individuals start considering adoption.
total_population-Consider_Adopting-Adopter
rejecting_rate
considering
person
Potential_Adopter*normal_considering_rate
+
adoption_from_word_of_mouth
People/year
Initial value is assumed to be 5% of the non-adopting population at start: (5,600,000 − 80,000) * 0.05 ≈ 276,000 people. This is an initial condition only.
276000
considering
rejecting_rate
adopting
person
Number of individuals rejecting adoption and leaving Consider Adopting. The value is constrained to be non-negative, ensuring realistic behaviour.
MAX(0, fractional_rejection_rate*Consider_Adopting)
People/year
Flow representing the rate at which individuals move from Consider Adopting to Adopter, driven by a baseline adoption rate and amplified by overall product attractiveness.
Consider_Adopting
*
initial_adoption_rate
*(1+attractiveness_multiplier)
People/year
How many vegetarians there are in Norway in 2000.
initial_adopter
adopting
person
Average annual consumption of plant-based meat alternatives per adopter.
The value (42 kg/person/year) reflects partial substitution of meat, estimated using Norwegian consumption statistics and nutritional protein requirements.
42
kg/person/year
Current price of plant-based alternatives, determined by the initial price level adjusted by the effect of cumulative consumption.
initial_price_plant_based*effect_of_consumption_on_price
kroner/kg
Average retail price of meat in Norway, set to 200 NOK per kg based on consumer price data.
200
kroner/kg
Price of plant-based alternatives relative to meat.
price_of_plant_based_alternative/price_of_meat
dmnl
Reference level of perceived taste. Represents the minimum taste level at which taste begins to positively influence adoption.
0.6
taste
Level of social skepticism toward plant-based alternatives, influencing adoption decisions among individuals who are considering adoption.
initial_skepticism
Growth_in_skepticism
skepticism_reduction
skepticism
Rate at which skepticism increases, depending on the distance to the maximum skepticism level and the effect of rejection.
((max_skepticism-Skepticism)
/
normal_growth_in_skepticism)
*
Effect_of_rejection_on_skepticism_gain
skepticism/year
Rate at which skepticism decreases, depending on current skepticism and social influence from adopters.
(Skepticism/normal_reduction_in_skepticism)
*
effect_of_adopters_on_skepticism
skepticism/year
Total consumption of plant-based alternatives by adopters.
Adopter*consumption_per_adopter
kg/year
Determines how quickly taste improves over time, independent of consumption effects. Set to 0.03 to reflect gradual product improvement.
0.03
1/year
Initial perceived taste of plant-based alternatives, measured on a normalized scale.
0.3
taste
Baseline fraction of individuals in Consider Adopting who reject adoption at model start, set to 0.5.
0.5
1/year
Characteristic time over which skepticism declines under normal conditions.
11
year
https://nofima.no/publikasjon/2041712/
Expected number of contacts per adopter per year with individuals who are considering adoption.
probability_of_contacting_a_potential_adopter
*
contact_rate_with_adopter
person/year
Adoption driven by word-of-mouth interactions between adopters and non-adopters. The flow depends on the number of contacts, the share of contacts with potential adopters, and the probability that a contact results in adoption.
adoption_fraction*potentials_contacts_with_adopters
People/year
The probability that a contact with an adopter converts a potential adopter into an adopter.
initial_adoption_fraction*effect_of_skepticism_on_adoption_fraction
dmnl
Represents how increasing skepticism reduces the likelihood that individuals who are considering adoption will actually adopt. Low skepticism has little effect on adoption, while high skepticism strongly suppresses the adoption fraction.
relative_skepticism
2,1.975,1.913,1.767,1.465,1,0.5352,0.2331,0.08682,0.02526,0
dmnl
Represents how perceived plant-based taste contributes to overall product attractiveness. The effect is zero below the taste threshold and increases once taste exceeds this level.
relative_plant_based_taste
0,0,0,0,0,1,1.134,1.317,1.5
dmnl
Shows how attractiveness decreases as the relative price of meat substitutes increases, lowering adoption incentives.
relative_price
0.1,0.29,0.48,0.67,0.86,1,1.24,1.43,1.62,1.81,2
2,1.975,1.914,1.768,1.467,1,0.5425,0.2419,0.09639,0.03514,0.01
dmnl
0,01
0.01
1/year
Measures how attractive meat substitutes are overall.
Higher values indicate that favorable price and taste make adoption more likely, while lower values reduce adoption.
initial_attractiveness
+
((effect_of_price_on_attractiveness*weight_of_price)
+
(effect_of_taste_on_attractiveness*weight_of_taste))
dmnl
Total population describes the time-dependent population level, modeled as exponential growth from the initial population at the start of the simulation, governed by a constant population growth rate.
Initial_population*EXP(Growth_rate_population*(TIME-STARTTIME))
People
Probability that an adopter’s social contact involves a potential adopter rather than an existing adopter or non-interested individual.
Potential_Adopter/total_population
dmnl
Baseline attractiveness at model start, normalized to 1.
1
dmnl
Stock representing the perceived taste of plant-based alternatives. The level increases over time through the flow change in taste, which depends on remaining improvement potential, a baseline improvement rate, and consumption-driven learning effects.
initial_taste
change_in_taste
taste
Represents the rate at which the perceived taste of plant-based alternatives improves over time. Taste increases proportionally to the remaining improvement potential (distance to the maximum taste level), scaled by a base improvement rate and amplified by increased consumption through learning and innovation effects.
(max_taste-"Taste_of_plant-based")
*
taste_improvement_rate
*
effect_of_consumption_on_taste
taste/year
Represents the starting level of skepticism toward adopting plant-based alternatives.
0.7
skepticism
Represents how strong skepticism is compared to its maximum possible level. Values close to zero indicate low skepticism, while values close to one indicate skepticism near its upper bound.
Skepticism/max_skepticism
dmnl
Baseline probability that a contact with an adopter leads to adoption, representing the initial strength of imitation and peer influence.
0.05
dmnl
Total consumption of plant-based alternatives at model start.
initial_adopter*consumption_per_adopter
kg/year
Consumption of plant-based alternatives relative to the initial consumption level.
total_consumption/initial_consumption
dmnl
Captures how increasing consumption lowers the price of plant-based alternatives.
Higher relative consumption reduces price through learning effects and economies of scale.
relative_consumption
1,0.9886,0.9609,0.8951,0.7592,0.55,0.3408,0.2049,0.1391,0.1114,0.1
dmnl
Captures how increased consumption drives taste improvement through learning and innovation, with diminishing returns at higher consumption levels.
relative_consumption
1,1.013,1.043,1.117,1.268,1.5,1.732,1.883,1.957,1.987,2
dmnl
Initial price of plant-based alternatives at the start of the simulation, set high to reflect early-stage products with limited availability and high production costs, rather than actual retail prices.
700
kroner/kg
Number of adopters relative to the initial level.
Adopter/initial_adopter
dmnl
Represents how the number of adopters influences skepticism. As the relative number of adopters increases, skepticism is increasingly reduced, reflecting social normalization and increased familiarity.
relative_adopters
0.818,0.869,1,1.278,1.585,1.909,2.472,2.864,2.966,2.992,3
dmnl
Defines the reference upper level of skepticism on the model’s normalized scale, where 1 corresponds to a complete rejection-oriented attitude. Values above 1 represent amplified skepticism effects (e.g., strong negative narratives) and are handled through the graphical functions.
1
skepticism
Characteristic time over which skepticism grows under normal conditions.
7
year
Initial stock of adopters at model start, representing the estimated number of early adopters (80,000).
80000
person
Baseline rejection rate based on the size of the considering population.
Consider_Adopting*initial_rate
People/year
Represents how rejection contributes to growth of skepticism. Higher rejection rates lead to an increase in skepticism, with diminishing additional effects at higher rejection levels.
relative_rejecting_rate
0,0.3,0.6,1,1.2,1.5,1.8,2.1,2.4,2.7,3
0.545,0.636,0.739,1,1.068,1.307,1.511,1.682,1.807,1.875,1.875
dmnl
Perceived plant-based taste relative to the threshold level.
"Taste_of_plant-based"/taste_threshold
dmnl
Relative importance of price in determining overall attractiveness, defined in relation to the importance of taste.
1-weight_of_taste
dmnl
Relative importance of taste in determining overall attractiveness.
Set to 0.5, reflecting literature suggesting that taste and price are of comparable importance in food choice decisions.
0.5
dmnl
Fraction of individuals in Consider Adopting who reject adoption, starting from a baseline level and reduced by higher product attractiveness.
initial_fractional_rejecting_rate*effect_of_attractiveness_on_rejection
1/year
Represents how overall product attractiveness influences the rejection rate. Higher attractiveness reduces the tendency of individuals to reject adoption, while low attractiveness increases rejection.
attractiveness_multiplier
0.01,0.309,0.608,1,1.206,1.505,1.804,2.103,2.402,2.701,3
1.344,1.301,1.199,1.054,1.003,0.889,0.882,0.868,0.855,0.855,0.848
dmnl
Annual share of people who try plant-based products without others (it's personal interest)
0.03
1/year
Total number of social contacts per year generated by adopters.
Adopter*contact_rate_per_year
person/year
The frequency of meaningful encounters by adopters per year.
Drives the potential contact flow; higher values accelerate imitation.
3
1/year
Constant annual population growth rate (0.9% per year).
0.009
1/year
Norwegian population in year 2000.
4478497
People
Baseline rejection fraction used as a reference level, represents rejection at model start.
0.5
1/year
Normalized measure of the rejection rate, calculated as the current rejection rate relative to the normal rejection rate.
rejecting_rate/Normal_rejection_rate
dmnl
LOOPSCORE(adopting,Adopter,total_consumption,relative_consumption,effect_of_consumption_on_taste,change_in_taste,"Taste_of_plant-based",relative_plant_based_taste,effect_of_taste_on_attractiveness,attractiveness_multiplier)
dmnl
Represents the highest level of taste that plant-based alternatives can achieve in the model, reflecting that improvements eventually reach a ceiling.
1
taste
LOOPSCORE(considering,Consider_Adopting,rejecting_rate,Potential_Adopter)
dmnl
LOOPSCORE(considering,Consider_Adopting,rejecting_rate,Potential_Adopter,probability_of_contacting_a_potential_adopter,potentials_contacts_with_adopters,adoption_from_word_of_mouth)
dmnl
LOOPSCORE(adopting,Adopter,contact_rate_with_adopter,potentials_contacts_with_adopters,adoption_from_word_of_mouth,considering,Consider_Adopting)
dmnl
LOOPSCORE(change_in_taste,"Taste_of_plant-based")
dmnl
LOOPSCORE(Growth_in_skepticism,Skepticism)
dmnl
LOOPSCORE(considering,Consider_Adopting,Normal_rejection_rate,relative_rejecting_rate,Effect_of_rejection_on_skepticism_gain,Growth_in_skepticism,Skepticism,relative_skepticism,effect_of_skepticism_on_adoption_fraction,adoption_fraction,adoption_from_word_of_mouth)
dmnl
LOOPSCORE(adopting,Adopter,total_consumption,relative_consumption,effect_of_consumption_on_price,price_of_plant_based_alternative,relative_price,effect_of_price_on_attractiveness,attractiveness_multiplier)
dmnl
LOOPSCORE(adopting,Adopter,relative_adopters,effect_of_adopters_on_skepticism,skepticism_reduction,Skepticism,relative_skepticism,effect_of_skepticism_on_adoption_fraction,adoption_fraction,adoption_from_word_of_mouth,considering,Consider_Adopting)
dmnl
price_of_plant_based_alternative
relative_price
price_of_meat
relative_price
Consider_Adopting
rejecting_rate
Potential_Adopter
considering
Consider_Adopting
adopting
Skepticism
skepticism_reduction
normal_reduction_in_skepticism
skepticism_reduction