Micro-level explanations for emergent patterns of self-governance arrangements in small-scale fisheries—A modeling approach

Small-scale fisheries (SSFs) in developing countries are expected to play a significant role in poverty alleviation and enhancing food security in the decades to come. To realize this expectation, a better understanding of their informal self-governance arrangements is critical for developing policies that can improve fishers’ livelihoods and lead to sustainable ecosystem stewardship. The goal of this paper is to develop a more nuanced understanding of micro-level factors—such as fishers’ characteristics and behavior—to explain observed differences in self-governance arrangements in Northwest Mexico. We focus on two ubiquitous forms of self-governance: hierarchical non-cooperative arrangements between fishers and fishbuyers, such as patron-client relationships (PCs), versus more cooperative arrangements amongst fishers, such as fishing cooperatives (co-ops). We developed an agent-based model of an archetypical SSF that captures key hypotheses from in-depth fieldwork in Northwest Mexico of fishers’ day-to-day fishing and trading. Results from our model indicate that high diversity in fishers’ reliability, and low initial trust between co-op members, makes co-ops’ establishment difficult. PCs cope better with this kind of diversity because, in contrast to co-ops, they have more flexibility in choosing whom to work with. However, once co-ops establish, they cope better with seasonal variability in fish abundance and provide long-term security for the fishers. We argue that existing levels of trust and diversity among fishers matter for different self-governance arrangements to establish and persist, and should therefore be taken into account when developing better, targeted policies for improved SSFs governance.

. ODD+D protocol including guiding questions, examples and column for own model description, bold font denotes newly developed parts compared to the original ODD protocol [1]. a) What is the effect of micro-level factors related to trust -such as fishers' reliability, and loyalty between fishbuyers and fishers and between members in coops-for the establishment and persistence of different self-governance arrangements? b) How does environmental variability affect whether co-ops or PCs will emerge as the dominant form of self-governance? c) How stable are these two self-governance arrangements and what makes them fail? The focus is on increased system understanding.

I.ii.b
For who is the model designed?

Scientists, students/teachers, decision makers, stakeholders
For scientists, particularly those interested in self-governance in social-ecological systems. For decision-makers to illustrate how e.g. social attributes can influence whether cooperative vs. non-cooperative forms of self-governance can establish and persist. Global level: form-coop (one co-op forms), processes, pseudo-code of the schedule, synchronous / asynchronous update fisher-turns-buyer (the fisher with highest capital turns buyer), set-shares-demandprice (a fixed market share is given to each buyer and co-op, this is also their demand. The buyers demand is what they strive to meet in supply from their fishers. The price given to fishers by the buyer or coop is fixed (co-ops give market price, fish buyer give 80% of the market price).

DAILY (every time step):
See main paper a flow chart figure.

combinations of theory and observations
Fishers decision-model on whether to cheat on their fishbuyer or not and land and sell their catch to another buyer is based on empirical observations. Fishbuyers decide which fisher to work with based on empirical observations. Co-op members will decide to kick out a member if this person is not fulfilling the assigned undertakings, based on empirical observations. See S1 Table for a complete table linking each activity in the model to the empirical justification. Buyers are satisfiers, i.e., they want to fulfill their market share but not more.
Buyers choose fishbuyers based on social attributes and fishing skills (their reputation as fishers), and stop working with them based on the loyalty developed between them. The objective is to get the most reliable and loyal fishing crew.

II.ii.c How do agents make their decisions? Decision tree, utility function, random choice
Decision is based on a set of rules: Buyers decide on what fisher to work with (takes the fisher with maximum reputation).
Fisher decides to cheat based on loyalty and reliability. See S1 Calculations.

Cultural norms, trust
Yes, trust is incorporated though loyalty that forms over time.

Space-theory based models
No.

Discounting, memory
Yes though the loyalty that forms between fishers and buyers, and fishers in a co-op.

Not at all / stochastic elements mimic uncertainties in agents' behavior / agents explicitly consider uncertain situations or risk
Not included.

II.iii Learning
II.iii.a Is individual learning included in the decision process? How do individuals change their decision rules over time as consequence of their experience?

Change of aspiration levels depending on past experiences
No learning is included. However, loyalty changes over time and affects the decision.

Evolution, genetic algorithms
No. Sensing is often assumed to be local, but can happen through networks or can even be assumed to be global.

II.iv Individual
Simply assumed to know them.

II.iv.e Are costs for cognition and costs for gathering information included in the model?
No.

Extrapolation from experience, from spatial observations
Buyers assess their fishers' catch in the next time step by aggregating the catch of its fishing crew in the current time step.
II.v.b What internal models are agents assumed to use to estimate future conditions or consequences of their decisions? None.

II.v.c Might agents be erroneous in the prediction process, and how is it implemented? (External) uncertainty, (internal) capability of the agent
The assessed catch will be somewhat erroneous because of changes in stock and number of active fishers.

II.vi Interaction
II.vi.a Are interactions among agents and entities assumed as direct or indirect?

Direct interactions, indirect interactions (mediated by the environment / the market, auction)
Direct between fishers in a co-op or in a PC relationship. Direct between marketbuyer. Direct between fisher and biological entity. Indirect between buyer and fish-stock, indirect between fisher and market.

Spatial distances (neighborhood), networks, type of agent
On their network and type of agent.
If they are in a PC or co-op type of network.

Explicit messages (Matthews et al., 2007)
The interactions involve communication but it is not explicitly represented. represented?

II.vi.d If a coordination network exists, how does it affect the agent behaviour?
Is the structure of the network imposed or emergent?
Centralized vs. decentralized, group based tasks The cooperative structure is imposed on fishers within a co-op and influences which other fishers they interact with (e.g. form loyalty, share economic returns). The PC structure is also imposed on six random inactive fishers, where the financially strongest inactive fisher becomes the fish buyer. The structure is hereafter emergent. III.iv.c How were submodels designed or chosen, and how were they parameterized and then tested?
Justifications, references to literature, independent implementation, testing, calibration, analysis of submodels See S1 Table.