Methodology

The third pillar is the methodological domain: how we measure constructs, identify effects, and infer from data to claims. Substantive questions and construct definitions are inert until method turns them into evidence. This pillar is where a measure becomes a number (metrics, scales, surveys, preference elicitation), where a number becomes an estimate (modeling, empirical and analytical models, structural and reduced-form econometrics), and where an estimate earns a causal interpretation (identification, experiments, quasi-experiments).

The chapters here range from the foundational—what counts as good measurement, how to build and validate a model—to the frontier methods that define quantitative marketing today: structural demand estimation, causal inference and field experiments, discrete-choice and Bayesian methods, and the industrial-organization tradition. The unifying idea is that method is not a neutral afterthought but a source of substantive claims in its own right: the identification strategy is the argument.