behavioural economics in social-ecological systems with thresholds
TRANSCRIPT
Behavioural Experiments in Social-Ecological Systems with Thresholds
Juan C. Rocha, Caroline Schill, Anne-Sophie Crepin & Therese Lindahl
@juanrocha
How does people behave when dealing with situations pervaded by threshold (uncertainty)?
Framed field experiment• 256 participants / 4 fishing
communities
• Largely depend on natural resources as main source of income
• History of regime shifts - critical transitions:
• Mangroves collapse (1980s -90s)
• Hypoxia events and fish deadlines
Recent hypoxia events - 2016
SeptemberJuly August Last week
A day of field work
• Dynamic game • Monetary incentives: 1 fish worth 500 Pesos • Communication allowed throughout the
game • Participants did not know the # rounds to
be played • Session lasted about 3 hrs • Average earnings = ~20k COP ~€ 5.50;
range: 3,000 - 40,000 COP (+ show-up fee of 15,000 COP), about a daily wage, paid privately at the end of the session
Experimental design: set-up and procedure
Earnings paid privately at the end
Communication allowed
Monetary incentives
STAGE 1: 6 rounds
For all groups the same, independent of treatment
Baseline
Dynamic common pool resource game
Start
STAGE 1: 6 rounds
For all groups the same, independent of treatment
Baseline
STAGE 2: 10 rounds
All groups start again with 50 resource stock units
Dynamic common pool resource game
Start
STAGE 1: 6 rounds
For all groups the same, independent of treatment
Threshold• climate event has happened
Baseline
STAGE 2: 10 rounds
All groups start again with 50 resource stock units
Dynamic common pool resource game
Start
STAGE 1: 6 rounds
For all groups the same, independent of treatment
Threshold• climate event has happened
Risk• long-lasting climate event might
happen, known probability (0.5)
Baseline
STAGE 2: 10 rounds
All groups start again with 50 resource stock units
Dynamic common pool resource game
Start
STAGE 1: 6 rounds
For all groups the same, independent of treatment
Threshold• climate event has happened
Ambiguity• long-lasting climate event might
happen, unknown probability
Risk• long-lasting climate event might
happen, known probability (0.5)
Baseline
STAGE 2: 10 rounds
All groups start again with 50 resource stock units
Dynamic common pool resource game
Start
STAGE 1: 6 rounds
For all groups the same, independent of treatment
Baseline• no change
Threshold• climate event has happened
Ambiguity• long-lasting climate event might
happen, unknown probability
Risk• long-lasting climate event might
happen, known probability (0.5)
Baseline
STAGE 2: 10 rounds
All groups start again with 50 resource stock units
Dynamic common pool resource game
Start
Visualisations
Monetary incentives
Decision cards
Result 1: there is a treatment effect at group level
Groups in the threshold, risk and uncertainty treatment achieved a higher average stock size over time.
Pairwise Wilcox text (Bonferroni adjusted)
BaselineRiskThresholdRisk0.00160--Threshold0.000161.00000-Uncertainty8.1e-110.017820.00041
Fishermen facing thresholds presented a more conservative behaviour on the exploration of the parameter space of
resource exploitation.
Buenavista
Las Flores
Tasajeras
Result 2: Treatment effect at individual level
• Threshold: • Base line = 20
• Treatments = 28
• Cooperation = (StockSize - Threshold / 4) - IndExtraction
• Are there fisher styles?
BuenavistaLasFloresTagangaLasFlores2.6e-11--Taganga0.00038<2e-16-Tasajera0.02236<2e-160.10150
Pairwise Wilcox text (Bonferroni adjusted)
Result 2: Treatment effect at individual level
• Threshold: • Base line = 20
• Treatments = 28
• Cooperation = (StockSize - Threshold / 4) - IndExtraction
• Are there fisher styles?
BuenavistaLasFloresTagangaLasFlores2.6e-11--Taganga0.00038<2e-16-Tasajera0.02236<2e-160.10150
Pairwise Wilcox text (Bonferroni adjusted)
Random effects panel model shows that treatment, place and time have significant effects on cooperation, but effect differs if at group or individual levels.
Taganga
What’s going on in these areas?
Lower education and older population
Dramatic changes?
Buenavista & Las Flores have experience more abrupt changes
Buenavista
Poorest, and they are on their own
Las Flores
Lots of cooperatives but weak cooperation
Concluding remarks• Fishermen facing (uncertain) thresholds
exhibit a more precautionary behaviour as a group
• Speculation collapse:
• groups come often from communities with higher livelihood diversification, lower resource dependence
• and strongly exposed to infrastructure development
• Higher noise on resource dynamics masks the relationship between fishing efforts and stock size encouraging a more explorative behaviour of fishing effort in real life.
Questions? e-mail: [email protected] twitter: @juanrocha
slides: http://criticaltransitions.wordpress.com/
Experimental design of dynamic CPR game: communication of risk/ uncertainty
Risk Uncertainty
+ 8 of unknown colour
(Constant) probability of 0.5 that the event happens in following round
(Constant) probability range between 1/10 and 9/10 that the event happens in following round