Introduction

Hello everyone!
I’m excited to announce the release of our latest collaborative effort (R package), designed to make complex consumer price and inflation calculations a breeze: emWeightedCPI .
Here I will Introduce you to what this package is about.

What is emWeightedCPI?

Our R package “emWeightedCPI” (hosted on github) stands for Expenditure based and Multivariate Weighted Consumer Price Index. This is the result of the combined effort of myself and two other talented individuals; Dr Paul A. Agbodza and George K. Agyen . It is a versatile tool that simplifies the calculation of standard Consumer Price Indices (CPI) and Inflation using Expenditure based and Multivariate Weights. The package automates a proposed multivariate weighted indexing scheme for price data. More information can be found [here].

Why Create emWeightedCPI Package?

Normally CPI is calculated from household expenditure data obtained from household expenditure surveys. However, these surveys are expensive making it difficult to conduct on a regular basis. This package introduces an alternative weighting approach that enables the computation of variable weights using price data only.

This approach is convenient since it does not require incurring additional cost for conducting household expenditure survey to generate CPI for the determination of inflation figures. Even so, one can still generate the Laspeyres’ CPI and inflation using this package.

The workings of The package

Using emWeightedCPI is as easy as taking a stroll! Begin by installing the package from github by using

install.packages(“devtools”) 

devtools::install_github(“JC-Ayimah/emWeightedCPI”)

Once installed, load the package into your R environment with library(emWeightedCPI) . Now you’re all set to dive into the world emWeightedCPI and make use of its functions

How does emWeightedCPI work?

The package contains four main functions:

1. mvw_cpi: This function calculates the multivariate weighted indices . It requires only one argument (data); a price dataset containing prices of various items for a base year and a current year. It then calculates four index values (CPI values) based on the data provided and returns them as a named vector
2. mvw_inflation: Using the index values calculated by mvw_cpi, the mvw_inflation function computes the inflation rate based on the selected index. The function takes two arguments index and data . the index argument takes one of four possible values (indexes); ‘fisher’, ‘paashe’,‘laspeyres’ and ‘drobish’. The data argument requires the price dataset from which the inflation is to be determined.
3. eb_cpi: This function calculates consumer price indexI from expenditure based expenses. The function takes in two inputs, a price data and an expenditure data. The index calculated from this function is the ‘Laspeyres index’
4. eb_inflation: Like the mvw_inflation function, the eb_inflation function also calculates inflation based on the index calculated from the eb_cpi function. The function takes the same arguments specified in the eb_cpi function.
   
   Usage Examples

Lets create a price data containing the prices of 4 different items for a base year and current year.

#create an arbitrary price data

mypriceData <- data.frame(x1=runif(50, 9.9, 13.7), x2=rnorm(50, 10.9, 2.1), x3=runif(50, 12.2, 15), x4=runif(50,19.4, 24), # base year prices y1=runif(50, 26, 30), y2=runif(50, 31, 38.9), y3=runif(50, 28.2, 33.1), y4=runif(50, 51.8, 60)# current year prices )

To calculate the multivariate weighted indices simply use;

library(emWeightedCPI)

indices <- mvw_cpi(data = mypriceData)

indices

To calculate the multivariate weighted inflation based on a specific index (let’s say ‘fishers’) we use;

inflation_value <- mvw_inflation(index = ‘fisher’, data = mypriceData) inflation_value

The expenditure based index eb_cpi and inflation eb_inflation can also be calculated easily by using the codes as shown below. We need to generate an expenditure data to use together with our previously created price data in order to calculate the expenditure based index and inflation.

#pick the average base year prices from mypriceData

n_vec <- apply(mypriceData[, 1:4], 2, mean)

n_vec

#combine the output above into a dataframe with two columns and same

#number of rows as number of price items to create expenditure data

myexpData <- cbind.data.frame(item = names(n_vec), price = (unname(n_vec)))

myexpData

#calculate expenditure based CPI

exp_index <- eb_cpi(price_data = mypriceData, expenditure_data = myexpData)

exp_index

#calculate expenditure based Inflation

exp_inflation <- eb_inflation(mypriceData, myexpData)

exp_inflation

Conclusion

Innovation often thrives when minds come together, and emWeightedCPI is a testament to the power of collaboration. We’re incredibly proud of what we’ve achieved with this package, and we hope it becomes a valuable asset in your analytical toolkit.

Why Use emWeightedCPI?

1. Ease of Use: The functions in emWeightedCPI are designed to be intuitive and straightforward to use.
2. Flexibility: Users can customize the calculations based on their specific requirements by adjusting the input parameters especially for the mvw_inflation function
3. Efficiency: With optimized algorithms, emWeightedCPI delivers fast and accurate results.

Get Started with emWeightedCPI Today!

If you’re looking to simplify your consumer price index and inflation rate calculations in R, give emWeightedCPI a try! You can install it directly from github using:

install.packages(“devtools”)devtools::install_github(“JC-Ayimah/emWeightedCPI”)

For more information and detailed documentation, check out the emWeightedCPI GitHub repository.

We hope you find emWeightedCPI as useful and exciting as we do! Feel free to reach out with any questions, feedback, or suggestions.

Happy calculating!