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Sortition

// Random Juror Selection

Governance

Randomly selects participants to serve in decision-making capacities for specific periods or tasks.

Sortition operates by first establishing a pool of eligible candidates based on predefined criteria, such as token holdings, identity verification, or onchain history. From this pool, the system employs a verifiable random function (VRF) or other cryptographically secure randomization method to select a subset of participants. These randomly chosen individuals are then granted temporary authority to evaluate proposals, make decisions, or perform specialized governance functions. The selected cohort may operate within predefined constraints such as voting rules, deliberation requirements, or decision thresholds. After completing their service period, new participants are randomly selected, ensuring governance responsibility rotates throughout the community over time. The mechanism can incorporate multiple stages for qualification verification, training periods, or accountability measures to balance pure randomness with needed expertise.

The concept draws from classical Athenian democracy where citizens were randomly selected for public service. The practice later evolved through various implementations in medieval Italian city-states, particularly Venice and Florence, where it was combined with voting systems to prevent corruption and political manipulation. In blockchain, stake-weighted sortition has been used in the selection of validators in Proof-of-Stake networks like Tezos, as well as in the random juror selection within decentralized arbitration protocols like Kleros.

Advantages

  • Statistical Representation: Achieves better demographic and intellectual diversity than elections or appointments.
  • Corruption Resistance: Even when it is stake-weighted sortition, it reduces political entrenchment by giving all eligible participants a chance to become decision-makers.
  • Reduced Coordination: Eliminates expensive campaigning and coalition-building processes while maintaining legitimacy.

Limitations & Risks

  • Expertise Gaps: Random selection may result in participants lacking specialized knowledge needed for complex governance decisions, potentially leading to suboptimal outcomes.
  • Commitment Issues: Randomly selected participants may have lower engagement levels compared to self-selected candidates, affecting decision quality and participation rates.
  • Statistical Variance: Small selection pools or bias in who responds to selections can produce unrepresentative outcomes.
  • Gaming Vulnerability: In stake-weighted systems, wealthy actors could concentrate resources during selection periods to increase their selection probability.

Design Considerations

  • Selection Pool Parameters: Define minimum stake or participation requirements that balance inclusivity with skin-in-the-game.
  • Term Duration: Align term lengths with decision complexity and learning curves. Implement staggered rotations to maintain institutional knowledge.
  • Randomization Mechanism: Use verifiable random functions or commit-reveal schemes for transparent randomness. Implement multi-round selection processes to mitigate manipulation attempts.
  • Incentive Structure: Design compensation models that reward thorough participation. Implement stake-slashing conditions for dereliction of duties. Create reputation systems that track historical participation quality.

Examples

Kleros Jurors Sortition

Implements a multi-layered sortition system for decentralized dispute resolution. Jurors stake PNK tokens in specific subcourts (e.g., general, technical, financial) and are randomly selected using a commit-reveal scheme for random number generation. Selection probability is weighted by both stake amount and subcourt specialization. The protocol implements an appeal system where each subsequent round requires more jurors, selected through the same sortition process but with higher stakes required.

Tezos Liquid Proof-of-Stake

Implements sortition through its "Liquid Proof-of-Stake" consensus where bakers (validators) are randomly selected to propose and validate blocks. The mechanism uses a deterministic pseudo-random number generator seeded by data from previous blocks to ensure unbiased selection. Selection probability is proportional to a baker's stake, requiring a minimum of 6,000 XTZ to participate. The system includes a "roll" concept where every 6,000 XTZ equals one roll in the selection lottery.

sDAO

Utilizes Chainlink's Verifiable Random Function (VRF) to randomly select a statistically representative subset of voters ("jurors") from the broader DAO community. The system integrates with WorldCoin for Sybil resistance, ensuring each human participant can only be selected once. Selected jurors receive financial incentives from the treasury to encourage active participation, with each juror having equal voting power regardless of token holdings. This implementation promotes community engagement by incentivizing members to stay informed about proposals, as anyone might be selected to vote. By decoupling financial stake from governance power within the selected cohort, the system aims to reduce plutocratic influences while maintaining representative decision-making through statistical sampling.