Price and Quantity Indices for International Comparisons: The EKS, CCD, and the Geary-Khamis real income indices.
Basic functionality tests are implemented, with some reasonable unit tests.
Installation
You can install the development version of pppindexr from GitHub with:
# install.packages("devtools")
devtools::install_github("ErikOSorensen/pppindexr")Example
Let us look at a 3x2 example (three countries of unequal size, two goods) and define some arbitrary prices and quantities (one row per country):
library(pppindexr)
ex1 <- data.frame(
population = c(1, 2, 3),
p1 = c(1, 2, 1),
p2 = c(1, 1, 3),
q1 = c(1, 1, 1),
q2 = c(3, 1, 2)
)
# CCD, EKS, and Gheary Khamis indices:
ex1$eks = eks(ex1[, 2:3], ex1[, 4:5])
ex1$ccd = ccd(ex1[, 2:3], ex1[, 4:5])
ex1$gk = ygk(ex1[, 2:3], ex1[, 4:5],
pop = ex1$population, min_scale=TRUE)
ex1 |> knitr::kable(digits=3)| population | p1 | p2 | q1 | q2 | eks | ccd | gk |
|---|---|---|---|---|---|---|---|
| 1 | 1 | 1 | 1 | 3 | 1.915 | 1.902 | 2.151 |
| 2 | 2 | 1 | 1 | 1 | 1.000 | 1.000 | 1.000 |
| 3 | 1 | 3 | 1 | 2 | 1.456 | 1.440 | 1.576 |
The quantity indices are scaled with respect to the “country” with the lowest real income.