At the level of Choice, mechanisms specify the causal processes by which an individual decision-maker produces an admissible selection from a set of alternatives. These mechanisms do not define preferences, constraints, or optimality conditions; those are specified by the domain’s laws and invariants. Instead, choice mechanisms describe how evaluations, restrictions, and selections are procedurally carried out within those constraints.
Choice mechanisms operate entirely at the individual level. They transform preference orderings, feasibility constraints, and probabilistic structures into realized selections or observable choice behavior. Each mechanism acts on defined entities and variables, produces state change, and remains subject to the governing laws of choice. No mechanism at this level presupposes interaction with other agents or aggregate structure.
By isolating these mechanisms, the template distinguishes between what must be true for choice to be valid and how valid choices are generated in practice. This separation prevents axioms, laws, and representational theorems from being conflated with the processes that produce observed decisions.
SAT – Structure – Mechanisms – Choice (Microeconomic Foundations)
| Mechanism | Definition | Entities | Properties | Variables | Laws / Relations | Invariants Preserved | Conditions |
|---|---|---|---|---|---|---|---|
| Preference Comparison | Evaluation of admissible alternatives relative to an ordering over outcomes. | Decision-maker; alternatives | Preference ordering; comparability | Preference relations | Completeness; Transitivity | Symmetry; Stability | Well-defined option set |
| Constraint Filtering | Elimination of inadmissible alternatives prior to selection. | Decision-maker; alternatives | Feasibility; resource limits | Feasible set | Feasibility (Constraint Satisfaction) | Balance | Defined constraints |
| Optimization / Selection | Selection of a non-dominated alternative from the feasible set. | Decision-maker; alternatives | Preference ordering; dominance | Chosen option | No Dominated Choice; Optimality Conditions | Optimality | Comparable alternatives |
| Revealed Choice Mapping | Inference of consistent choice relations from observed selections. | Decision-maker; observed choices | Behavioral consistency | Choice correspondence | Consistency of Choice (Revealed Preference) | Stability | Stable preferences across observations |
| Stochastic Selection | Probabilistic selection among alternatives under a stable choice structure. | Decision-maker; alternatives | Choice probabilities | Selection frequencies | Stochastic Choice Regularity | Distribution | Random utility regime |
Taken together, the mechanisms of Choice form a closed procedural core for microeconomic foundations. They account for evaluation of alternatives, restriction by constraints, selection among feasible options, inference of preference structure from behavior, and probabilistic variation in choice. Each mechanism produces admissible outcomes while preserving the invariants required by choice theory.
These mechanisms do not explain why preferences exist, how they are formed, or how they change over time. They also do not imply equilibrium, coordination, or efficiency beyond what the laws of choice already require. Their role is narrower and more precise: to specify the causal processes that turn admissible preference structures into concrete selections.
Choice mechanisms therefore supply the necessary bridge between abstract decision constraints and observable behavior. Only once these mechanisms are made explicit can interaction mechanisms operate coherently and aggregate mechanisms be meaningfully defined.