beezdemand (version 0.2.0)

get_empirical_measures: Calculate Empirical Demand Measures

Description

Calculates empirical (model-free) measures of demand from purchase task data. These metrics characterize consumption patterns without fitting a demand curve model.

This is the modern replacement for GetEmpirical(), returning a structured S3 object with dedicated methods for printing, summarizing, and visualizing.

Usage

get_empirical_measures(data, x_var = "x", y_var = "y", id_var = "id")

Value

An S3 object of class beezdemand_empirical containing:

• measures - Data frame with one row per subject and columns:

  • id - Subject identifier

  • Intensity - Consumption at lowest price (demand intensity)

  • BP0 - Breakpoint 0: first price where consumption = 0

  • BP1 - Breakpoint 1: last price with non-zero consumption

  • Omaxe - Empirical Omax: maximum total expenditure (price × consumption)

  • Pmaxe - Empirical Pmax: price at which maximum expenditure occurs

• call - The matched call

• data_summary - List with n_subjects, has_zeros, and complete_cases

Arguments

data

A data frame in long format with columns for subject ID, price, and consumption

x_var

Character string specifying the column name for price (default: "x")

y_var

Character string specifying the column name for consumption (default: "y")

id_var

Character string specifying the column name for subject ID (default: "id")

Details

Empirical Measures

• Intensity - The consumption value at the lowest price point. Reflects unrestricted demand or preferred level of consumption.

• BP0 (Breakpoint 0) - The first price at which consumption drops to zero. If consumption never reaches zero, BP0 = NA. Indicates the price threshold where the commodity becomes unaffordable or undesirable.

• BP1 (Breakpoint 1) - The highest price at which consumption is still non-zero. If all consumption is zero, BP1 = NA. Represents the upper limit of the commodity's value to the consumer.

• Omaxe (Empirical Omax) - The maximum observed expenditure across all prices (max of price × consumption). Represents peak spending on the commodity.

• Pmaxe (Empirical Pmax) - The price at which maximum expenditure occurs. If maximum expenditure is zero, Pmaxe = 0. If multiple prices have the same maximum expenditure, the highest price is returned.

See Also

• GetEmpirical() - Legacy function (superseded)

• plot.beezdemand_empirical() - Visualization method

• summary.beezdemand_empirical() - Extended summary

Examples

# \donttest{
data(apt, package = "beezdemand")

# Calculate empirical measures
emp <- get_empirical_measures(apt)
print(emp)

# View measures table
emp$measures

# Extended summary with distribution info
summary(emp)

# Visualize distribution of measures
plot(emp)  # histogram by default
plot(emp, type = "matrix")  # scatterplot matrix
# }