About the HPT Resource Index
The Hypothetical Purchase Task (HPT) is a behavioral-economic method for measuring demand — how much of a commodity people say they would consume across a range of prices. This index catalogs published and preprint HPT studies so researchers can see, at a glance, what has been studied, how, and with which demand models.
What's coded per study
- Study identification — year, journal, DOI, URL, publication status, open-access status
- Commodity — the good or behavior under study and its domain (e.g., substance, food, behavioral)
- Study design — design type, participant assignment, whether individual and/or aggregate demand curves were analyzed
- Participants — country, region, sample size, population, mean age
- Price schedule — number of prices tested, price range, currency
- Demand model — which model was fit (e.g., exponential, exponentiated, linear) and the
kvalue used - Indices reported — which demand indices (alpha, Q0, breakpoint, Pmax, essential value, R²) each study reports, plus their mean values
Methodology & scope
This is a curated, living index rather than a formal systematic or scoping review. Treat this as ongoing curation, not a claim of exhaustive literature coverage.
What counts as an HPT study. We include studies using the Hypothetical Purchase Task (HPT) methodology specifically — not delay, probability, effort, or social discounting studies, which use a related but distinct framework. HPT studies are usually price-based, but we also include hypothetical budget-allocation studies that substitute a different constraint for price (e.g., likelihood of success rather than a dollar amount), when the underlying demand-curve logic is the same.
How studies are identified. The index began from Jacobs & Bickel's (1999) original HPT paper — the study that introduced the methodology. This is not an exhaustive multi-database systematic search, so coverage will grow over time rather than being complete from the start.
About PROMISE Labs Africa
The HPT Resource Index is a project of PROMISE Labs Africa, a 501(c)(3) scientific nonprofit dedicated to cutting-edge translational behavioral research in Africa — rapidly testing innovative interventions in simulated environments to understand, predict, and influence real-world behaviors.
Acknowledgments
Thank you to our research assistants, Deborah Odaudu and Osajimere Atalor, for their work compiling and coding the studies in this index.