mksc-theory-development

Model & Mechanism Development (mksc-theory-development)

When to trigger

• The phenomenon is interesting but there is no formal model yet
• The "mechanism" is verbal and needs to be written as primitives, payoffs, and equilibrium
• A structural story lacks an identification argument (what variation pins down each parameter)
• An analytical model lacks crisp comparative statics or testable predictions

In Marketing Science, "theory" means a model

Unlike behavior-first venues where theory is a verbal mechanism, here a contribution is carried by a mathematical model. Build whichever genre the question demands.

Analytical (game-theoretic) models

• State primitives: players (firms, consumers, platform), action spaces, information structure, timing, and payoffs.
• Solve for equilibrium (Nash/subgame-perfect/Bayesian) and prove existence/uniqueness where needed.
• Derive comparative statics — sign how equilibrium prices, advertising, or profits move with a parameter — and surface the counterintuitive result that is the contribution.
• Keep assumptions transparent and motivated by marketing institutions (double marginalization, competitive response, targeting).

Structural econometric models

• Write a demand model (random-coefficients/BLP logit, nested logit, dynamic discrete choice) and, where relevant, a supply/equilibrium condition (FOCs, pricing game).
• State micro-foundations: utility, state transitions, firm objective.
• Make the identification argument explicit before estimation: which moments/instruments (cost shifters, BLP instruments, exclusion restrictions, panel variation, experiments/discontinuities) identify preferences, dynamics, and supply parameters — and why they are exogenous.
• Define the counterfactual the estimated model will simulate; the model must be rich enough to answer it and no richer.

Connecting reduced-form or behavioral evidence

If you include experiments, surveys, or reduced-form results, tie them to the model: as model-free evidence motivating an assumption, as a source of identifying variation, or as validation of a mechanism the model formalizes.

Checklist

• [ ] Primitives (players, actions, information, timing, payoffs) fully specified
• [ ] Equilibrium concept stated; existence/uniqueness addressed (analytical)
• [ ] Comparative statics / testable predictions derived (analytical)
• [ ] Demand (and supply) specified with micro-foundations (structural)
• [ ] Identification argument explicit: variation/instruments → each parameter
• [ ] The counterfactual question the model must answer is named up front

Anti-patterns

• A regression relabeled as "a model" with no primitives or equilibrium.
• A structural model with parameters but no identification argument.
• Assumptions chosen for tractability that contradict the marketing institution.
• Comparative statics asserted, not derived.

Theory pass for Marketing Science

Treat this skill as an executable review pass, not a prose hint. First lock the demand/supply mechanism, fit evidence, and counterfactual decision margin; then judge whether the current manuscript answers the venue's real reader: quantitative marketing reviewers who read the model through the managerial counterfactual it makes possible.

• Do the pass: Name the construct, mechanism, boundary condition, and falsifiable implication separately; do not let a literature summary masquerade as theory.
• Return a ledger: give claim / evidence / risk / manuscript location rows, so the next agent can edit rather than rediscover the issue.
• Sibling guard: compare against Journal of Marketing Research for empirical marketing breadth, Management Science for wider OR/MS reach, Quantitative Marketing and Economics for specialist modeling; if a sibling owns the contribution, recommend re-routing before polishing format.
• Stop condition: do not give submission-ready advice until the pack's resources/official-source-map.md has been checked for volatile rules and the manuscript has one concrete fix for the largest venue-specific risk.

Output format

【Genre】analytical / structural
【Primitives】players, actions, info, timing, payoffs
【Equilibrium / estimand】concept; existence/uniqueness OR demand+supply
【Identification】variation/instruments → parameters; exogeneity logic
【Predictions / counterfactual】key comparative static OR policy to simulate
【Next step】mksc-literature-positioning then mksc-methods