param-registry: Parameter Naming Registry for beezdemand
In beezdemand: Behavioral Economic Easy Demand

param-registry

R Documentation

Parameter Naming Registry for beezdemand

Description

This file defines canonical parameter naming conventions across all model families. It serves as the single source of truth for parameter names, scales, and mappings.

Naming Convention

Parameters follow snake_case with scale prefixes:

log10_<param>: parameter in log10 space (e.g., log10_alpha)
log_<param>: parameter in natural log space (e.g., log_alpha)
natural_<param>: parameter in natural/linear space (e.g., natural_alpha)
<param>: canonical name without prefix (context determines scale)

Equation Registry

Equations are grouped by model family:

NLS (FitCurves): hs, koff, linear. The k parameter defaults to fixed but supports multiple modes: "fit", "ind", "share", "range".
NLME (fit_demand_mixed): zben, nlme_simplified, nlme_exponentiated. Only nlme_exponentiated uses k (always fixed).
Hurdle Part II (fit_demand_hurdle): hurdle_zhao, hurdle_hs, hurdle_snd. Parameters are in log space. hurdle_snd has no k parameter. Each variant has 2RE and 3RE sub-models with different variance/correlation parameters.
Cross-price (fit_cp_nls): cp_exponential, cp_exponentiated, cp_additive. All use log10_qalone, I, log10_beta.

Derived Metrics Naming

pmax_model: Pmax derived from fitted model parameters
pmax_obs: Pmax from observed/empirical data (max expenditure price)
omax_model: Omax derived from fitted model parameters
omax_obs: Omax from observed/empirical data
alpha_star: Normalized alpha (Strategy B; Rzeszutek et al., 2025). Makes alpha comparable across different k values by adjusting for the scaling constant. Computed as \alpha^* = -\alpha / \ln(1 - 1/(k \cdot \ln(b))) where b is the logarithmic base (10 for HS/Koff, e for hurdle models). Returned by FitCurves, tidy() on fixed fits, and tidy() on hurdle fits. Standard error (alpha_star_se) is obtained via the delta method. Requires k \cdot \ln(b) > 1; otherwise NA is returned.